If you DID, why are you asking us to tell you how?

Create different social media strictly for the app and use that to reach out to people, ask your friends for a shoutout, just dm a bunch of people in all platforms. It’s a very tiresome process but u got this. Besides this just simply u could use this channel erasu.

Try creating fb page or tg channel and also use cross promotion in tg channels with good view perday they ask for money but it's relatively cheap.

Use Facebook and Instagram ads

Good

What kind is ur app i want to see you

Contact me if you want telegram channel promotion