Create own relay to access Synology NAS?

Is there any way to replicate QuickConnect but using your own server? I want to be able to use Synology Photos app to backup and access photos when not connected to our local network.

I dont want to use Tailscale or another VPN because that requires the VPN to be running on my device. I dont want to use QuickConnect because I dont like how Synology decrypts my data on their relay server. I dont want to open ports on my local network for DDNS.

Basically, I want the features of QuickConnect but with my own relay server. Is that possible?