Can I use a free hosting address like netlify.app or vercel.app?

Not as the site address of a placement. Addresses on hosting platforms, such as netlify.app, vercel.app, pages.dev or github.io, and free domain endings such as .tk or .ml, are shared by thousands of sites, so we cannot confirm that one of them is yours.

What works:

• Your own domain. Most registrars sell one for a few dollars a year. A subdomain of your own domain, like app.yoursite.com, is fine too.
• Your app's store listing. A public Google Play or App Store page can be your placement instead of a website.

If you are stuck, open a ticket with your address and tell us about your project.