What is the ruling on praying behind an Imam who is an innovator (mubtadi') and an enemy of the Sunnah, and is it obligatory for a worshiper to travel 200 km to perform Friday prayer in another place if all the mosques in his area are like that?

It is not obligatory to travel the aforementioned distance to attend Jumu'ah (Friday prayer) or congregational prayers, nor is it permissible to abandon Jumu'ah on the pretext that the Imam is an innovator (mubtadi'). Rather, one must pray behind him. If the Imam is an innovator, as mentioned, then the discussion regarding praying behind people of innovation has already been presented.