I think you need to know the other person from elsewhere, and get them to share their address with you out-of-band. Like, in person (best), or over another messaging app
Discussion
I'd say there are 2 types of apps people want. One is for boring IRL contacts. Numerous options.
The other one is for random online weirdos. Telegram is dominating this field now. But Nostr format is better for public conversations.