In Prove It on Roblox, the key appears to go into the lock/door puzzle in the HQ area , not just anywhere on the map. The most relevant walkthrough snippet says there’s a gravestone with an “A” at the back of the HQ and a John Doe model at the top, which suggests the key is part of that specific hidden sequence rather than a random item.

What to do

  • Go to the HQ area.
  • Check the back of the HQ for the gravestone clue.
  • Then look toward the top of the HQ where the John Doe model is mentioned.
  • Use the key on the matching lock/interaction point tied to that puzzle path.

Why this is the likely spot

The search results for “Prove it” mostly point to that same HQ mystery rather than a generic key slot, so the key is probably used for a clue-based unlock in that section.

Quick note

If you meant a different Roblox game with a similar name, the key location could be totally different.