Wireguard VPN Flint2

Unfortunately I know enough to screw things up. Yes I read the tutorial but a lot of it is like reading a foreign language.

I have Flint2 w/4.7 firmware. I'm behind Verizon FIOS with dynamic IP. I set up Cloudns.net for DDNS purposes.
Wireguard I used through the router, I did not sign up for any of the services when you go the VPN Daschoard and click set up.
I enabled the wireguard server, created a configuration file and it actually worked yesterday, but today everything stopped working. ChatGPT (which I used to set this up) got me all turned around so I wiped the router and I'm starting over.

I'm connecting to a static IP on my local network through the VPN.
When I click DDNS for the config file it adds xxxx.glddns.com:51820 but shouldn't this be safeofficetunnel.ip-ddns.com? That's what I did earlier and it worked. IF DDNS is updating at Cloudns then it is basically the same as using my public ip address/51820 as the endpoint, correct?
I would glinet's ddns service but I don't understand how to change the name to safeofficetunnel.glddns.com. If I use gl's ddns does my URL to log in have to be whatever the router kicks out? e.g wr5c544.glddns.com:51820?

The DDNS function within the GUI will only and always add the GLDDNS, not any other DDNS you might use.

If you use a custom DDNS you need to change the config file manually before uploading it to a WireGuard client.

OK. Wireguard (WG) running.
*8.1 accesses the router and *.8.250 accesses the file share set up on the local network(static IP)
However, xxxxxxxxxglddns.com only goes to the router page. I thought the whole point of DDNS was the router knowing the local IP (in case it changed) so the user could enter xxxxxxxxxglddns.com and that address would know to forward to real local IP.
I mean it's not a big deal to fire up WG and type in *.8.250 or click a mapped drive...just wondering.