Firstly, if you’re connecting your phone, make sure it’s angled up slightly so your whole body and feet are in frame. If you’re using a laptop, ensure your entire body is visible as well.
Secondly, you need to perform the exercise fully to get a ‘clean’ rep. Make sure you’re following the coach's instructions. For instance, if you’re doing a squat, you’ll need to drop down low enough to get a rep.