welcome to the forum,
might try rclone bisync
or
read about https://rclone.org/docs/#u-update
or
a manual sync
https://forum.rclone.org/t/recommendations-for-using-rclone-with-a-minio-10m-files/14472/4
https://forum.rclone.org/t/how-to-sync-s3-with-millions-of-files-at-root/36703/6