The payment info will vary depending on what payment method you used, here is what you should send:
In-app purchase - If you paid with an in-app purchase using Android (we can't track iOS or Amazon payments unfortunately), please send us the Play Store transaction ID, in the format: GPA-xxxx-xxxx-xxxx-xxxxx
Paypal - If you made the transaction with a Paypal account, provide the transaction ID as well as the date of the payment.
Credit Card - If you paid with a credit card on our website, please provide the last 4 digits of the card, the date of transaction and the amount paid.
Bitcoin/Crypto - If you paid with Crypto, you will need to provide the transaction ID that Coinpayments sent you after payment
License Code - If you used an 8-digit code from a third party to upgrade, please send us the code.
I don't have email on my free account
If you don't have an email on your account and you have never paid for any upgrades, there is unfortunately no way track down your username as we have no information that we can search for on our end.