Thank you for the source o7

You do not need to be, but a LGBTQ+ person will probably have more ‘experience’ with this discrimination and thus know when it’s bad. They can often recognise it earlier and better, exactly because they themselves often are the victims of it, and experience the effects.

If you’re not LGBTQ+, you don’t really experience homophobia yourself. That said, you should still call it out.