A lot of people aren’t big fans of Nginx Proxy Manager, which is separate from Nginx. But I like it. It’s got a nice gui, and the part I really like is the letsencrypt ssl certs baked in. You can get a new one, for a new service with a click of a button, and it auto renews your certs, so you don’t have to worry about it once it’s set up.
Some advice, TrueNAS isn’t very newbie friendly. Between permissions and their wonky kubernettes setup that no containers actually leverage, it’s not great. It is free, but expect bumps in the road. Unraid and OpenMediaVault are much easier to use. I switched to Unraid, and it’s been amazing, I highly recommend it. It’s nice that you can install random sized drives, they don’t need to match. You can toss in a few ssds for cache, and the docker containers are super easy to setup and maintain. Jellyfin works just fine for instance. OMV has some great offerings too, but lack the docker/VM hosting side. It’s a NAS and nothing else. It’s expected to have proxmox or something hosted elsewhere that uses OMV as storage.
#2 opinion, build your own NAS. Especially if you’ve already built your own Gaming PC, it’s pretty straight forward. Pick a low powered cpu, toss in some ram, a ton of hdds, and maybe some old graphics card you have lying around for transcoding or hosting local AI for kicks. You’ll get a lot more for your money this way.