I don't know what the rules are in the US regarding a protest vote, but that's what I do in the UK as long as the candidates I have to choose from (local or general) all make my skin crawl. If you don't represent my interests, you don't get my vote, and neither red nor blue team even pretend to care about people like me at this point, so:

https://www.votenone.org.uk/protest_votes_count.html

Oh, and just to pre-empt any "you're why people like Trump get in", no you. The system is literally designed this way -

https://www.newyorker.com/magazine/2022/08/22/american-democracy-was-never-designed-to-be-democratic-eric-holder-our-unfinished-march-nick-seabrook-one-person-one-vote-jacob-grumbach-laboratories-against-democracy

https://www.counterpunch.org/2020/10/14/liberalism-and-fascism-partners-in-crime/

https://truthout.org/articles/fascism-is-possible-not-in-spite-of-liberal-capitalism-but-because-of-it/

https://nyanarchist.wordpress.com/2019/01/23/scratch-a-liberal-a-fascist-bleeds-how-the-so-called-middle-class-has-enabled-oppression-for-centuries/