To install Poste Italiane app like PostePay, PosteID e BancoPoste occorre installare prima il market F-Droid¹ e a quello installare il market Aurora e poi su Aurora² si trovano le app di Poste Italiane.
¹ Aurora Store | F-Droid - Free and Open Source Android App Repository
² Aurora Store for Android - Download the APK from Uptodown
However, at the moment the PosteID does not work because it requires the upgrade of Google Play Services which can be downloaded form Aurora or from Uptodown³.
³ Google Play Services for Android - Download the APK from Uptodown
However also in the last version 23.02.14, it does not allow PosteID to work. Therefore, the problem is somewhere in its configuration and not in the version.