Deployment on a Digital Ocean DropLet with nginx

Hello
I am in the process of deploying my meteor application on a ‘droplet’ of ‘digital Ocean’ with ‘meteor up’.
A little hassle to configure ‘mup.js’ and finally the deployment is Ok.

However, in order for ‘mup deploy’ to work through to completion, I need to shut down my ‘nginx’ server. Otherwise the following error occurs:

Started TaskList: Start Meteor
[xxx.xxx.xxx.xxx] - Start Meteor
[xxx.xxx.xxx.xxx] x Start Meteor: FAILED
------------------------------------STDERR------------------------------------
Removing docker containers. Errors about nonexistent endpoints and containers are normal.
Error response from daemon: endpoint test not found
Error: No such container: test-frontend
Error response from daemon: endpoint test-frontend not found
Error: No such container: test-nginx-letsencrypt
Error response from daemon: endpoint test-nginx-letsencrypt not found
Error: No such container: test-nginx-proxy
Error response from daemon: endpoint test-nginx-proxy not found
Finished removing docker containers
docker: Error response from daemon: driver failed programming external connectivity on endpoint test (69d3da3e78d0eb7464005a4861b093af10d0844846099298f75281525153e6f4): Error starting userland proxy: listen tcp 0.0.0.0:80: bind: address already in use.

I think this is a problem with port 80.

Can anyone tell me what I need to do to fix this problem.
Thank you for your answers.

Yvan