Messages

A little late but...
You didn´t specify if you have a certificate, but anyway:
a) I installed my certificate (and its bundle)
b) configured the web gui to use such certificate
c) configured the web gui to listen to some port
d) created a rule on WAN interface:
WAN interface
any Source
Destination WAN address
from selected port to same port
Redirect target IP    127.0.0.1
Redirect target port   configured port (could be different for security. Don´t use any known port for the "from" part)
Use a good description to remind you that it´s not recommended to open management to the outside

Regards