I support trans people's right to live free from discrimination & prejudice. As do all the gender critical feminists I know & respect.
What amounts to "discrimination" is going to be controversial here, (is it real discrimination to stop someone from self-ID-ing into a group they wouldn't otherwise belong to?), but certainly, GC feminists aren't calling for anything like the historic persecution of Jewish people.
Neither do (compelety false) antisemitic ideas like pseudo-scientific racial theories, or the idea that Jews ritually kill Christian children say, really compare with the completely true statement that you can't biologically change your sex; that biology is unquestionably important in some contexts like sport; and biology is arguably, reasonably, important in certain other contexts also.
What this charity is doing is just poisoning the public debate and trying to demonize their ideological opponents, because that strategy unfortunately can work well for them, and it's probably a lot easier than having to defend their position.