"No Builds Available" for internal users, although app is waiting for review

Hello! I've seen a year old thread on this with no solutions. I've uploaded my build to Testflight and my app is Waiting for review. This means internal users should be able to test it, however when i go to send the application to them it states there are no builds available. This is very frustrating, is there anything i've missed? Any help is greatly appreciated

Here is a screenshot of what it looks like when i go to send the build to my users

Thank you, Sofia