The election is already under way, so does that rule out the first option?
The Electoral College, but the members are not, in quite a few states, free to vote other than as directed by law, and in 14 states their votes are actually cancelled if they vote for any but the pledged candidate.
Actually, that's determined by state law and, as such, may be so where you live, but not everywhere[0].
[0] https://www.forbes.com/sites/danielcassady/2020/09/05/electi...