Is there any provision in US constitution which allows one candidate, say Jo Jorgensen, to “donate” their votes in a given state to another candidate?
No, there is nothing in the Constitution that allows the transfer of votes from one candidate to another. However, this year Maine used Ranked-Choice Voting (RCV). Under RCV, voters for Jo Jorgensen or other candidates could have selected Trump or Biden as their second choice; thus transferring their votes. No other states allow RCV for president.
Court rules in favor of Sec. of State clearing way for RCV in presidential election, September 22, 2020.
Maine will become the first state in US history to use ranked-choice voting in a presidential election.
No, a candidate cannot agree to "donate" votes to another candidate in any state.
The closest any state has to this is ranked-choice voting in Maine. In Maine (or in either of its congressional districts), if no candidate gets to 50% of the first-choice vote, then the candidate with the fewest votes is eliminated, and the votes cast for that candidate in the first round will then count for the voter's second choice. This is repeated until one candidate does get above 50%.
It could happen that Jorgensen's voters could put Trump on a higher preference than Biden, which would lead to many of Jorgensen's votes going to Trump in subsequent rounds. But that would be up to the voters to decide, not the candidates.
First of all, the elections of the last tuesday only serve for each state to chose its electors for the Electoral College who will be ones to actually chose the President.
Electoral laws are mostly a matter of state laws, not the US Constitution. So any such provision would belong to each state electoral laws. AFAIK, none provides for this.
As most of the states follow a "winner gets all of the electoral votes", in any of those states Jo Jorgensen would have to be the most voted candidate to have any actual electoral vote at all. That is not going to happen.
Even if in an state electoral votes were distributed proportionally, those are few (one for each congressist the state has). That would mean that Jo Jorgenssen would need a sizeable fraction of the popular vote in that state to get an elector. Quite improbable.
Even is she gets some electoral vote there is the question if Jo Jorgenssen could order the states to design some elector for Trump instead of for her, or demand the electors chosen in her name to vote for someone else when the Electoral College convenes.
That is more arguable, since it could depend also on state laws.
Some states have laws against unfaithful electors that punish electors who do not vote as instructed by the state and some claim that votes cast against instructions by the state are invalid, but the legallity of these laws is still unclear, as it would be the fact that if those laws would apply if it was the candidate herself requesting such a vote.
In short, the US Constitution does not have anything to say about this and even if it is allowed it would affect most likely presidential electors, of which Jo Jorgensen will most likely get none at all.
No, votes in election are not transferable to another candidate and she won't get any electoral votes.
If she really wanted to give her votes to another candidate she shouldn't have run in the first place but supported that candidate directly. As a note there appears to be 4 races where the number of votes she received is more than the difference between Trump and Biden