Photo gallery that both is able to modify device storage and link to nextcloud?

I have both Nextcloud and Syncthing spinning under docker. I have a need for a photo gallery that is able to modify device directories and link to my nextcloud.

Seeing as, nextcloud already backs up my photos; I thought I would just syncthing that archive back to my phone so I can modify it with a photo gallery app.

Come to find out, I attempt to create a new access point via syncthing to the directory that is holding my photo syncs, but… nextcloud looks to be denying syncthing access to it’s directories, how do I allow syncthing to modify nextcloud folder contents?

Edit: I have a Google Pixel 6a that I have CalyxOS flashed on it. The gripe I have with it is, both camera taken photos and screenshots go to complete different directories. Luckily, nextcloud just compiles them and inserts them into the same directory.

I really, just need syncthing to be able to reference and modify nextcloud directories.