This is what AI spilled out about, untested by me:
To use the Google Play Store on Waydroid, you must initialize Waydroid with the GAPPS system image rather than the default vanilla image, and then register your device ID to pass Google Play certification.
Initialize Waydroid with GAPPS
Stop the current Waydroid session: sudo systemctl stop waydroid
Reset the existing initialization data: sudo waydroid session stop and sudo rm -rf /var/lib/waydroid /home/waydroid (Warning: this clears current data).
Restart the Waydroid container service: sudo systemctl start waydroid [1]
Register and Certify Your Device
Open the Google Play Store app inside Waydroid, and if it says your device is uncertified, open your Linux terminal.
Access the Waydroid container shell: sudo waydroid shell
Run this command inside the shell to get your Android ID: sqlite3 /data/data/com.google.android.gsf/databases/gservices.db "select * from main where name = 'android_id';"
Copy the long number string returned by that command.