Hey ​@Tyler_Durrett, thanks for reaching out! 

In order to upgrade your Figma account from a Professional plan to an Organization or Enterprise plan you will need to have a business domain email address, so this is currently expected.

Even if you do use your current email address for business purposes, it cannot be an “@gmail.com” or “@yahoo.com” email address. In order to upgrade, you must have a “@YOURBUSINESS.com” business domain email address.