Upgrading on Docker - Portainer Documentation
docs.portainer.io › v › ce-2In other words, when you're installing or upgrading to Portainer 2.9.1 make sure all of the agents are also on version 2.9.1. Upgrading your Portainer Server Starting from Portainer CE 2.9, HTTPS is enabled by default on port 9443. These instructions will configure Portainer to use both 9443 for HTTPS and 9000 for HTTP.