Setup NextBox App Remote Access HTTPS/TLS Status

The good news is: Remote Access works - with Domain provided by deSEC behind Router Fritz.Box 7590.
The status messages A are : “Successfully resolved” for [IP4] and IP6]

My question: under Nextbox App Remote Access HTTPS/TLS Status:
How should I deal with these status messages B:

"Failed reachability for: [external IP], [Domain dedyn io] for [IPv4]
"Failed reachability for: [external IP], 1 for [IPv6]

The given references to the docs nitrokey com / nextbox
Port-Forwarding for [IPv4] and
DNS-Rebind for [IPv6]
are taken into account as far as possible.

Thanks for your kind support
20.09.2022 16.00h

I think most likely your provider doesn’t allow this connection. So it is filtered away before it can reach your fritzbox. Often this can be solved by writing a mail to the provider stating that you would like to be able to access your home network from the outside