Whilst I would deeply sympathise with someone who had to vote for Biden despite feeling he is supporting genocide in Palestine, would Trump do any differently? In fact he would support genocide in various other places on top of the genocide in Palestine, including within the US (forced displacement based on ethnic grounds).
Now if you genuinely thought there was no chance of Trump winning fair enough, vote for the tooth fairy, don't vote, do whatever you like. But when your not voting adds to the very real possibility of an incredibly dangerous person taking office, I don't see that not voting for the opponent is your best option.
As long as Biden believes in democracy, there's a genuine possibility of being able to vote him and his party out at the end of the term, and you don't think he's openly spoiling to ruin everyone's lives, your best option is surely to vote for him but then lobby, campaign and protest against the policies you don't like and/or for the things you do want that aren't being done. What you need to do is make sure the extremist republican party as it has steadily become gets utterly annihilated at the polls so that they can re-evaluate their positions and hopefully start to contribute to a functional democratic system once again. The way to fix a democracy isn't to protest against the half sensible ones who've gone in a direction you don't like, it's to force the absolute loony tunes that have hijacked the discourse to bugger off and let somebody sensible have a go. If the loony tune in question hadn't already been president and you didn't already know exactly what a dickhead he is then I'd have some sympathy, but you've already had the inoculation so now it's 100% on you if you help let him in.
(I know you're not from the States btw, this is a hypothetical "you".)