💰In-App Purchases

you need to have an android developer account for this

Enable testing with your email

please go to your developer account then head to setup ->License testing then add a new license tester (the email that you will be using for testing)

Submit your app for internal testing

before you roll out for production, export your app from google play as a signed .aab file then submit it to internal testing from your google play account (you should do this in order to be able to add in-app products)

Add in-app products

select your app and go to Products -> in-app products. they may ask you to create a payment profile, just add your payment method and tax information and adress...

Now, add 3 products under the same ID, you can customize the price but please make sure that the id is the same as the id in the picture