First, verify the following:
1) Make sure bluetooth is enabled on both devices (Settings > Bluetooth)
2) Make sure the privacy settings are enabled for both ScoreCam and Scoreboard Remote (Settings > Privacy > Bluetooth)
If that's not the issue, maybe try removing the apps, restarting the devices (important), and then reinstalling the apps, in that order.
Also check out this support document on Bluetooth: https://support.apple.com/en-us/HT201205bluetooth, scoreboard remote