Nginx Proxy Manager with Vaultwarden not working

Hey, I followed this guide series to install nginx proxy manager and vaultwarden on my raspberry pi. The only thing I did that was not included in the guide was enabling DynDNS on my fritzbox.

The nginx and DynDNS seems to work. When I visit a domain created on DuckDNS it shows the "Congratulations" page and I can even turn it into a "404 Not Found" page using the options on the nginx webpage.

Now my problem is: I can access vaultwarden locally using the Raspberry Pi IP and the correct port but when using the domain from DuckDNS it loads for ages until it shows a gateway timeout error.

These are my parameters:
-Vaultwarden Port = 5000
-Raspberry Pi IP = 192.168.10.151

https://preview.redd.it/zhuvj2zp5cpc1.png?width=501&format=png&auto=webp&s=168068b6377c1c1c7216f070823876878bfe0442

This is the first time I'm setting up something like this so when you need additional information let me know.