Are they physically forced to vote for Putin? And how widespread is the electoral fraud?
As to the widespreadness of the electoral fraud, it should suffice to know that Ela Pamfilova, the irremovable head of the Russian election circus, has recently proclaimed all video evidence of any fraud to be AI generated, and demonstrated a video where a casually-looking man throws a stack of doctored bulletins in, followed by several outright fictional characters.
Well, some decades ago if you were a school teacher, you were _asked_ to (1) vote "right" yourself (2) call all parents and ask them to vote "right". If you disobeyed, the school got problems and you got problems. Maybe not enough to make all people comply, but sufficient to get the right outcomes. Same goes for all government-funded workers.
Since then I think they simplified the system and just forge the results outright.
This is informative https://politics.stackexchange.com/a/27658/25206
tl;dr Other parties are Putin-like, and if/when a genuine alternative emerges, Putin deals with them ruthlessly. Example: Navalny was the charismatic leader of a small but popular rival party with anti-corruption policies. He was initially delegitimised (not allowed to partake in the 2018 elections due to [likely fake] charges of embezzlement), then poisoned (nearly died), then imprisoned, and then killed while in prison.
Consider the terrifying message that sends to would-be political rivals...
Before the latest Russian election one of the parties opposed the war in Ukraine and was a bit too popular, so, well, from https://en.wikipedia.org/wiki/Yabloko :
Also, several politicians associated with it were imprisoned, e.g. this guy: https://en.wikipedia.org/wiki/Lev_Shlosberg