Man, this is part of the onboarding I do regret. Wish I could point you to a self custodial solution with an LSP like we got with Phoenix, but most people use a custodian such as alby or in my case stacker.news

For stacker.news for example its username@website for your lightning address so in my case nerd2ninja@stacker.news and you know I'm not a primal user, but probably in your profile you enter that for your "LNURL"

Hope that helps and if not hope a primal user can explain better lol