If you just want the the 30-second answer, skip to the part in bold. (It may well become outdated though if Trump or his campaign put out something more substantive than that one-liner, which Reuters declared wasn't a "direct" clarification.)
TBH, and to supplement Ted's answer which is getting some flak, IMHO this is not so different with the kind of controversy he stirred with his "dictator for a day" phrase, back in winter. As WaPo related and commented on that:
On Wednesday, UMass Amherst released the results of a poll conducted by YouGov in which respondents were asked about the concept. The framing of the comment was stark, excluding Trump’s specific plans for using his theoretical dictatorial power. It was just, “Trump recently said that if elected, he would be a dictator only on the first day of his second term. Do you think that this is a good or bad idea for the country?”
A plurality of respondents said this was “definitely bad” with 6 in 10 saying it was “definitely” or “probably” bad. Among Republicans, though, a third said it was “definitely good” with three-quarters saying it was at least “probably” good.
[...]
Fox News host Maria Bartiromo asked him what he meant by it in an interview on Sunday, again framing it in the context of the concerns raised by outside observers. Trump said that he’d offered the idea “in jest.”
But also: “I’m going to close the border and we’re going to drill, baby, drill, that’s all,” he said. “And then after that, I’m not going to be a dictator.”
Did he mean executive orders, Bartiromo pressed? In response, Trump praised executive orders in general and suggested that President Biden was the one undercutting democracy.
In other words, he doesn’t really know. Think of it less as a plan than as an aspiration.
And yeah, he relished that controversy, even after after saying those remarkrs were in jest, because "a lot of people like it":
Whether or not he was kidding about bringing a tyrannical end to our 248-year experiment in democracy, I ask him, Don’t you see why many Americans see such talk of dictatorship as contrary to our most cherished principles? Trump says no. Quite the opposite, he insists. “I think a lot of people like it.”
And yeah, the pattern repeats. Pundits are now commenting what Trump could have possibly meant by 'You won't have to do it anymore'. Perhaps he'll explain again on Fox News, although thus far he appears not have done so in this case. Reuters on July 27:
Republican presidential candidate Donald Trump told Christians on Friday that if they vote for him this November, "in four years, you don't have to vote again. We'll have it fixed so good, you're not gonna have to vote." [...]
Trump campaign spokesperson Steven Cheung did not directly address Trump's remarks when asked to clarify them.
Cheung said Trump "was talking about uniting this country," and blamed "the divisive political environment" on the attempted assassination of Trump two weeks ago.
And yeah, Reuters also made the connection with previous "dictator for a day" issue, if you wonder about whether it's just me who thinks that's relevant...
So, if you buy the official clarification (which Reuters decided wasn't really a clarification), perhaps the Trump campaign favored interpretation [thus far] is that the US will be so united (in their thoughts/wants) under/after Trump that nobody will need to vote anymore. Of course, whether that's hyperbole as well...
N.B. WaPo's more recent (than Reuters') article quoted that more fully (and unlike Reuters did not declare it to be non-direct clarification):
Asked to clarify what Trump meant, Steven Cheung, a spokesperson for the campaign, said in a statement on Saturday that the former president “was talking about uniting this country and bringing prosperity to every American, as opposed to the divisive political environment that has sowed so much division and even resulted in an assassination attempt.”
Interestingly, WaPo also points out it wasn't the first remark of this (narrowly construed) kind by Trump:
In front of a different Christian audience last month, Trump made a similar suggestion about Christians not needing to vote after this year’s election.
At a Faith and Freedom Coalition event in Washington, the former president said Christians “don’t vote as much as they should.”
“Do you know the power you have if you would vote? … You’ve got to get out and vote, just this time. I don’t care — in four years, you don’t have to vote, okay? In four years, don’t vote,” he said. “I don’t care by that time, but we’ll have it all straightened out, so it’ll be much different.”
But if Democrats were to come into power, he said at the time, “they’ll ruin it [and] we’ll have to do this all over again.”
Erica De Bruin, a professor of government at Hamilton College whose research focuses on civil-military relations, civil war and policing, said, “Trump frequently makes these kinds of deliberately ambiguous statements that can be interpreted in multiple ways.” But she added that “to understand what another Trump presidency would involve, I think it is more useful to look at his past behavior than to attempt to parse what might be the ‘true meaning’ of any individual set of remarks he makes.” [...]
A related fact (perhaps) is that Trump essentially has said he was the best president ever (or at least “far greater than Ronald Reagan” ... mkay, he predicated that with "if his name weren’t Trump") and his (younger and/or less educated) supporters appear to believe it. When Trump made that kind of statement he substantiated it with his judicial nominees and his record on the environment and regulations. Reportedly his supporters plan a far greater overhaul of Washington if Trump gets re-elected, although interestingly Trump has recently claimed little knowledge of the latter.
In a broader context, it's probably no different of how Trump e.g. appears to promise he'll end all wars in world. Although he's deft enough not to claim he said something like that himself, but that e.g. [Hungary's PM] Viktor Orban said that about Trump. (Aside, this is common of how Trump introduces some such statements: "I hear people say..." etc.)
Update-ish: although these are not an official clarifications from Trump's campaign, but just from his many supporters, some sites deemed them newsworthy:
New Hampshire Gov. Chris Sununu [R] on Sunday dismissed Republican president nominee Donald Trump’s statement Friday telling people they “won’t have to vote anymore” if they elect him as standard Trump rhetoric.
“I think it was a classic Trumpism if you will,” he said to host Martha Raddatz on ABC’s “This Week.” [...]
“Obviously we want everybody to vote in all elections, but I think he was just trying to make a hyberbolic point that it can be fixed as long as he gets back into office and all that,” Sununu said.
(Wikipedia describes Sununu as a "reluctant" Trump supporter.) And
Sen. Tom Cotton (R-Ark.) said Sunday that President Trump was “obviously making a joke” when he urged Christian voters to vote for him in November and that, if they do, they “won’t have to vote anymore” because “everything” will be “fixed.”
“I think he’s obviously making a joke about how bad things had been under Joe Biden, and how good they’ll be if we send President Trump back to the White House so we can turn the country around,” Cotton said in an interview on CNN’s “State of the Union.”
(Wikipedia describes Cotton as a "Trump loyalist".)
So, we have similar explainers as for "dictator for a day", except these don't come straight from Trump's official campaign, but from his supporters (of all shades).