Amazon AppStore Unlocker no longer works for Sleep as Android

Detailed description of the problem:
I’ve used the Unlocker app from Amazon’s AppStore for years but Sleep As Android no longer recognizes the activation. I haven’t changed anything, it just stopped working yesterday.

Opening the Unlocker app shows this screen:

If I click Start, it just takes me to the App but without activation. If I try to use the Restore Purchase function in Sleep as Android it just takes me to the Play Store version.
Steps to reproduce:
Try to activate Sleep as Android with Amazon AppStore Unlocker.

Version of Sleep as Android:
Latest, 20230110

Hi, could you please contact directly? Thanks.