This data takes a while to be collated, for reasons further explained in my answer to this related question. Nevertheless, definitive data which can be used to accurately calculate this based on precinct data, rather than approximations based on county data, are in the process of being collated by the Daily Kos' elections team as part of their 'Pres-by-CD' project. This work was completed for the 2020 election on Feb 19th 2021.
Using their data, combined with the New York Times' feed for the House elections results, I have created the below visualization using a congressional district hex-map available here.
The total number of split districts in 2020 was 16 - nine districts elected a Republican representative, yet voted for Joe Biden, while seven districts elected a Democratic representative while voting for Donald Trump.
According to Vital Statistics on Congress, this is the lowest level of district-splitting, both in percentage and absolute terms, since 1920. That year, 11 out of 344 districts produced a split result. In 2016 and 2012, 35 and 26 districts (respectively) split their tickets.
The code used in this answer can be found on GitHub.