Firefox can’t establish a connection to the server at myserver.us6.quickconnect.to:32400

Plex Media Server NAS & Devices
4

For initial setup/claiming:

  1. You should be using RFC-1918 addressing (10.x.x.x, 172.16.x.x-172.31.x.x, 192.168.x.x.).
  2. You should be on the same network as the NAS.
  3. Using an incognito/private browser window, point your browser directly at the NAS.
    http://syno_ipv4_address:32400/web ← substitute the actual IPv4 address of your NAS. Note connection is http, not https.

Do not use quickconnect, a FQDN, DDNS, etc for initial setup/claiming.

If you are not using RFC-1918 addressing or are on a different network, you will have to establish a SSH tunnel to the NAS, to make you appear as a local user.