It’s not listed anywhere. You need to register to get access to the TestFlight beta. 

Where can I register to try the Aximmetry beta on my iPhone?. I'm from Mexico.

Hi Adrian,

I think it should work in Mexico too, just click on the link we shared with you in the email on your iPhone, then first install the Test Flight application, then install Aximmetry Eye. In each case, you should see a link\button on your phone's screen leading you to the next step.

Warmest regards,