Click the three lines button at the top left to open the sidebar. Then at the too right of that bar there is a drop down arrow. Clicking this will get you the option to add account. Clicking add account will give you the login prompt where you will put in your site url and credentials and should be good to go Best of luck.
For how new all of this is, or at least feels, I’ve been very impressed with the app and it’s features already in place.