Issue has now been resolved and build is now working.

You need to make a purchase for genuine copy of the software and also to activate the software by entering license key to get it to premium version. Free version has limited features and those limited functionality can work without activating it.

All of your links must work, you need to debug and check on console to get the exact issue:
https://websitetoapk.com/docs/debugging-with-chrome.html

All the apps created are as per the current accepted requirements of API Level 31.

Yes! Sure. But we recommend that you use JS API to show ads at whatever event you want to show.

Actually the Interstitial ad will be shown on selecting "Show Ad on App Launch"

You can surely download files with all the apps created using our software. Make sure to allow STORAGE permissions to save files.

If file links are from another domain, you should allow external URLs, else it will open in external browser.

It should usually stop playing anything when you close the app, can you please provide us with your APK so that we can test.

Kindly attach APK to us on the link below:
https://websitetoapk.com/support/submit_ticket

Kindly raise a support ticket:
https://websitetoapk.com/support/submit_ticket

Yes, All the apps created are fully google play compatible and suitable for publishing.