I have tried building my app (APK/AAB) many times, but the build process always fails with the same signing/build error, even after carefully following the instructions in your guide. Could you please help me identify the cause of this issue and advise me on how to resolve it?

Thank you for your assistance.
https://drive.google.com/drive/folders/1zanxQAS0ly7nbgOr0djltoxPcKhfAVai?usp=drive_link