You cant generally vote fascists out once they’ve sufficiently subverted or removed democratic processes, but they can be voted in especially if they’re the ones motivated to actually do so, their efforts to subvert those processes take a variable amount of time to complete that sometimes means they’re not totally done by the next election cycle, and even in the case of rigged/subverted elections, its not like they’ll suddenly become more fascist if people vote against them but won’t if people don’t do that.

It’s also not like voting, when possible, takes away a person’s ability to also try anything else. So, unless you have good reason to believe that a given election is actively dangerous, like that they’re only holding it to learn who would vote against them given the option or something like that, it makes sense to participate if the option exists.

Worst case, the election is meaningless and one wastes a small amount of time in trying it. Best case, you overestimated how much the process had already been subverted and the election system proves to be still functional. In neither case does casting a vote against someone that seems to be a fascist or similar make them more likely to succeed than if you’d simply stayed home.

If people voting against them did benefit fascists, they wouldn’t spend so much effort on undermining elections and voter intimidation, it would be counterproductive.