Can't figure out how to promote a player to GM

I read through the instructions on the wiki, and some other sources, and they all claim or imply I should be able to right click a user's name/icon, and in the resultant context menu, one of the options will be to promote them to GM. However, as you can see, I get no such option. Am I just being particularly dense and missing something? Any help would be greatly appreciated
Hi Jesse W! You have to do it from the settings menu for your module. Not in roll20. Just right click on the persons icon and you should get a drop down menu to promote them to GM. 
The Aaron
API Scripter
Hover their picture on the Game Details page. See:
Wow, thanks! That's the issue, alright! The wiki just vaguely says "hover over a player's icon". I forgot that the main game page has an icon list as well. Much appreciated!