How to acces site without port number

What I’m trying to do:
i have nginx as reverse proxy to acces paperless with my domain like :
paperless.baudouin.im

Where I’m stuck:
to access paperless from internet (WAN) it is mandatory to add port number like this
paperless.baudouin.im:XXXX
I would like not to have to add this port number, only the URL

nginx param are
server {
listen 443;
server_name paperless.baudouin.im

location / {
    proxy_pass http://192.168.1.ZZZ: XXXX;

What I’ve already tried:
My question is it possible acces paperless without le port number in the url adresse and nginx could add at the beginning as this is alway this port