Attempting to purchase an in-app purchase (to buy coins) in Minecraft on an Amazon Fire Tablet I was constantly being told that my Amazon password was incorrect.
The issue turned out to be down to OTP being enabled on my Amazon account, using Google Authenticator.
To resolve the issue, it involved entering the password, with the OTP added immedately on the end.
If OTP is 345678, and password is: MyPassword!
Then you’d enter: MyPassword!345678 in the password box.
Be quick though, the OTP only lasts for a few seconds!
Im having the same issue but it only allows me to put numbers in the otp verification part
When you do this you enter your password, but before you click “OK”, you append the password with the (current) OTP code, then you click “OK”. Was that what you were doing?