I used chatgpt to create the exact steps, commands and configurations I needed for my setup and achieved this the seemingly cheatful way. I used nginx and certbot. Worked like a charm. Congrats!
It's impressive that you was able to get it to help you correctly. It usually just spew things i need to fix that's why I didn't ask him, thank you for the tip.
Btw did you use a custom local domain name or did you use an actual domain ?
I just finished the SSL today, but have you gotten Syncthing GUI to work though? I can't seem to get it to work with the domain for some reason.