I’m working on a local chat app (https://convosphere.app https://convosphere.app) where people can talk within a custom radius without sharing numbers or person

I’m working on a local chat app (https://convosphere.app https://convosphere.app) where people can talk within a custom radius without sharing numbers or personal data. The main challenge now is onboarding — helping new users find nearby conversations even if few people are active yet. How would you design that experience? What are smart ways to seed engagement without faking activity?