error/local hub/cannotregisternotavailablesite

From MoodleDocs

To register to a hub your Moodle site needs to be accessible by the hub so the two can communicate bi-directionally.

The error indicates that the hub could not reach your site.

Reasons why you may have seen this error:

  1. Your site has a local address like http://localhost or http://127.0.0.1
  2. Your site is protected by a proxy or firewall
  3. Your site is blocked in some way