title: iOS Testflight invitation code
body: <p>I have my app written in Swift and have started testing using Testflight. Most of my users got the invitation email from Testflight and managed to install the beta version just fine.</p>
  
  <p>However, a few people did not get the email and resending (add remove the user from testflight) does not solve the issue. So I am thinking to use te "redeem" function by sending them an Testflight invitation code.</p>
  
  <p>How do I get such a code? (I checked in ITC but found nothing).
  Is this the same code fir all testers by the way?</p>