I don’t understand the meaning from @LukasReschke: You don’t need to add the IPs of the devices that access your Nextcloud. You only need to add the IP/domain of the Nextcloud server itself.
My situation: (as desribed here: NextCloud Box - Use of static IP address
I have an external static IP address
I assigned the nextcloud box an internal static address (192.168.1.30)
From my local network it is ok to access the nextcloud, but from the outside I have a problem and I can’t.
Witch IP do I have to add, to be able to access it from the internet