Below you can find some help and step by step instructions if you have Coin Hunt World Testflight issues.
How to be sure a Coin Hunt World iOS referral registers as valid:
1) have your referral install TestFlight: https://apps.apple.com/us/app/testflight/id899247664
2) have your referral install the game app: https://testflight.apple.com/join/2jlFVFVq
3) have your referral click your link or the Coin Hunt World Wiki referral https://coinhunt.gsc.im/4WKNyLAWyw before they build an HQ. If your link launches the game, the referral worked. You can verify this in this Stats page within your FRIENDS menu
4) If your link goes to the App Store instead of launching the game, have your referral restart their device, then long-press your link to “ open with” Coin Hunt