LycheeSync

Uploads photos from a selected album to your self-hosted Lychee open-source photo library (https://github.com/LycheeOrg/Lychee). After install, set your Lychee server's URL, and a username/password of a user that can upload - and then let it know which albums to upload. It'll keep a (clearable) log of what it uploaded to prevent duplicate uploads on subsequent syncs.