[Smush Pro] SMUSH PRO WONT ACTIVATE

No matter what I do I can't get Smush Pro to activate. I tried reinstalling the plugin, the WPMU DEV dashboard plugin is installed and activated, I tried logging off and on with my account within the dashboard, I also went to Smush > Settings and clicked on the Update API Status button. Nothing worked and I still only have the regular Smush plugin activated for the website.

How can I get Smush Pro working for this website? Thanks!