Running Nextcloud on Hyper-V, how do I "open it up" to the Internet?

Just to clarify something: I’m fairly new to Linux.

So, I set up a Nextcloud instance on Debian in a Hyper-V VM using this guide: Nextcloud 23 (Nextcloud Hub II) Installationsskript (all-in-one) für Ubuntu 20.04 focal fossa oder Debian 11 bullseye mit nginx, MariaDB, PHP8 fpm, Let’s Encrypt (acme), Redis, ufw und Fail2ban - Carsten Rieger IT-Services (It’s German.)

Now, I want to open it up to the Internet, so I can access the cloud from anywhere. The needed ports 80 and 443 are already port-forwarded by the router. I’m also running a DDNS client on the Windows machine.

If anyone can help me, I’ll be very grateful.

Greetings, John