My subscription flow was working, and it's been a month since I received the 'Something went wrong' error. I have two published apps, and both of them are encountering this error simultaneously. I've tried many solutions, but none of them worked.
Activity finished with resultCode 0 and billing's responseCode: 3
E/[Purchases] - ERROR(26164): BillingWrapper purchases failed to update: DebugMessage: . ErrorCode: BILLING_UNAVAILABLE.null
E/[Purchases] - ERROR(26164): PurchasesError(code=PurchaseNotAllowedError, underlyingErrorMessage=Error updating purchases. DebugMessage: . ErrorCode: BILLING_UNAVAILABLE., message='The device or user is not allowed to make the purchase.')