you can publish app for free but you should purchase the google play developer account at 25$ for lifetime and publish unlimited apps if you want any help you can check my app roja directa pirlo tv its upload on play store

https://play.google.com/store/apps/details?id=com.arteottica.myapp
friend I also published it on google play

You may publish an app for free, but you should pay $25 for a lifetime Google Play Developer account, which allows you to publish limitless applications. If you need help, check out my app, , which is available on the Google Play Store.

You probably need a .aab file to keep your app in the Google play store which requires to be purchased. The free version only allows you generate apk file to test it out.