Thank you
Os there another option than APK Mirror as also requires a credit card to verify my account?
Just to clarify, amethyst is not doing a kyc check. The Google play store is. Amethyst/nostr don't care who you are. That is google abiding by your local laws.
The APK release is downloadable from the GitHub repo and can be sideloaded. Like most Android apps, you don't have to install through Google play (a benefit of Android).
https://github.com/vitorpamplona/amethyst/releases/tag/v0.17.0
https://www.howtogeek.com/313433/how-to-sideload-apps-on-android/