Download and setup apps all while remotely connected using tailscale

[Thorshani]

I'm having trouble downloading and setting up apps on my NAS while accessing it remotely using tailscale. Apps such as File Browser and NextCloud. My only idea at the moment would be the IP address discrepancy between the app/NAS and the tailscale one. However, with NextCloud, at first the IP address was set to the one that the NAS uses on its remote LAN, and I was able to open the web interface oddly enough, but if I used NextCloud on my iPhone using either that IP or the tailscale IP of the NAS, I couldn't connect. If I tried to set the tailscale IP as the NextCloud IP, I couldn't even open the web interface.

Any ideas? How can I use these apps and upload files to my NAS remotely? I'm trying out the above apps to have cross-platform ability to upload and backup various files. Thanks!