You can do it with python - https://pypi.org/project/gphotos-sync. They have docker image too. I have a cron job that starts the docker container periodically to fetch any new photos.

i found gphoto sync is suitable for that. https://pypi.org/project/gphotos-sync/

bump. that's sound a good alternative! please get us a note on how to a(r)chieve that :)