Domain Issues

When I try and enter the domain in the facebook developers page I get this error:
This name must be derived from secure canvas URL, mobile site URL, unitary binary URL, site URL or Secure Page Tab URL.

When I try and authorize the app I get:

Given URL is not permitted by the Application configuration: One or more of the given URLs is not permitted by the App’s settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App’s domains.

https://bermondseystreetfestival.org.uk/

Can you help?

Thanks

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