Okay so I finally just happened upon "Advanced Profile Settings" when looking at something completely non-related to this problem and found the personal keys. Please update your documentation to specify that you need to look in profile -> advanced settings to find THESE keys. Also I'm now confused what the non-personal api keys are for.
Josh, what documentation do you want to get adjusted. Supply the exact url. And the exact lines you want to get adjusted.
Even better, you can adjust them yourself by going to that page and click edit on the top right.
For detailed instructions on how to change Mendix documentation see: https://docs.mendix.com/developerportal/community-tools/contribute-to-the-mendix-documentation. I hope one day this will be common practice for any Mendix professional.