You can check the followings:
Check if you have received our invitation email for this test.
Check if the email you are using for Google Play or App Store is the same as what you filled in our recruitment questionnaire.
Please make sure you download the game via the link we send (iOS via TestFlight) and that your internet connection is stable. (*If the problem persists, please contact our customer service via Discord Channel or Website: EN http://undawnsupportsmp@garena.com)