Ultimate Guitar Pro is a cross-platform service, so if you purchased it on Android, you get the access on iOS and on the Web as well. Follow the steps to restore your Pro access on our website:
If you already have an Ultimate Guitar account:
1) Check which UG account you're using in your mobile app
2) Log in to the same account on our website
If you don't have a UG account yet:
1) Open the mobile app
2) Tap "account&settings" > "create account"
3) Tap "Restore purchases"