Since you realistically aren't going to get a community to change instances just because you don't like the instance its on, you really only have two options...

If you're determined to be on this community specifically, then you're just going to have to tolerate the instance's rules.

Otherwise, you can block that instance and try to look for a similar community in another instance. The double-edged sword of decentralisation is that you tend to get multiple similar communities in different places.