If you have the Zoom app, but are not signed in, you might get prompted to sign in from a screen similar to this one below:

or

Just select Sign in with SSO from the right or bottom of that screen. You may be taken to a screen asking for the url address (like below) if so, just make sure you have trine.zoom.us entered in that box and select the blue Continue button. 

You may automatically sign in, or you may be directed to a page asking for your Trine username and password. If you use Azure 2FA, you may be prompted to authenticate as well. 

Please reach out to IT Services if you need further assistance or 1:1 training. There are short, step-by-step tutorials for Faculty on using Zoom in the Moodle Faculty Training Resource area in Moodle.