New user, finding my way.  Several management questions/issues:

A) Trying to setup a custom Dynamic DNS update.

Option is available in this firmware, but I can't seem to figure how how to enable it.

The form asks for Interface, user, password, domain name, update interval, URL.

The service URL is of the form h t t p s colon slash slash  user:password at example dot com colon 1234 slash DDNS

   1234 is a port number; credentials are not required as long as the Authorization header is provided. (e.g. from the form)

The service determines the IP address from the connection, and the domain name to update from the username used to authenticate.

All that it requires is a periodic GET (With Basic authentication)

No matter what I put into the URL box, I get a red "Invalid Format" when it loses focus.

Questions:

Is the user:password in the URL the same as the username/password on the form?  If not, how are they related?

What does the router do with the domain name for a custom update?  The form complains if I leave it blank.  My service doesn't need it, but it can be specified.  Better if I could leave it blank.  Is it available in the URL with some magic mark?

In short, how should I fill in the form to get this service to work?

B) The world has embraced Let's Encrypt TLS certificates.  Please add an ACME client so that LE can be used.  LE certificates are free, but renew every 60 days.  So it must be automated.

C) SSH - might be an option for adding a 3rd-party ACME client.  But it seems only to accept password authentication.  Please support Public-Key authentication, which is much, much more secure!

D) The VPN Client manual indicates that WireGuard is an option.  The firmware doesn't seem to have it.  My other servers all use WireGuard.  Is it hiding on the router?  If not, another request: Please add it.  It's much easier to deal with, secure, and requires fewer computes than the alternatives...

These items aside, first impressions are very positive.