Day 3 post op

I had my ACL reconstruction and my lateral meniscus bucket handle and root tear repaired 3 days ago. In a locked zero degree brace for two weeks and only allowed to unlock for exercises.

Question is , when doing heel slides am I allowed to use my hands lift my brace to help with sliding my heel back or should i only achieve knee flexion with the strength of my leg ?

The image below shows the amount of flexion I can currently get , I’m hoping once my swelling gets under control I should be able to make much more progress