How do I add email addresses to the pull down menu on the setup tab?

If you click on the link in cell B30 of the Setup tab, it will take you to a separate sheet that contains the course information and email addresses that are accessed by the Meet Sheet.
Once you've opened the sheet, click on the 'Add emails here' tab and add the email in the first available slot at the bottom.
Be sure to add the school, name, email, and which season you want the email to be available for.
If you want the email available for multiple seasons, you will have to enter it twice, one time for each season.