I GOT THIS ERROR WHEN I TRIED TO DOCKER-COMPOSE UP -DI followed my nginx proxy manager installation from this tutorial. And after 5th step, my Synapse HomeServer is not working.
https://www.linode.com/docs/guides/using-nginx-proxy-manager/
I am using Element client, and its not working.
I did not try anything because I am afraid I will make another problem.
In your screenshot, your docker image seems to be using Traefik as a web server and the error indicates that port 443 is already allocated.
So I don't understand why you want to use nginx, which is also a web server and will also use port 443, hence the error you're having. Obviously there's a conflict, maybe you should look at the image creator for your needs ...
Well, you have to choose between Traefik and Nginx!