Pour the water into the bottom of your Instant Pot. Place the trivet in the pot, then set the crab leg clusters on top. Secure and seal the lid and cook on Manual High pressure for 2 minutes. Perform a quick pressure release.
Meanwhile, melt the butter in a microwave-safe bowl, then mix in the garlic cloves. Serve the crab legs with the garlic butter dipping sauce and lemon wedges, if desired.
Notes
HOW TO COOK CRAB LEGS FROM FROZEN:
Pour the water into the bottom of your Instant Pot. Place the trivet in the pot, then set the crab leg clusters on top. Secure and seal the lid and cook on Manual High pressure for 4 minutes. Perform a quick pressure release.
Meanwhile, melt the butter in a microwave-safe bowl, then mix in the garlic cloves. Serve the crab legs with the garlic butter dipping sauce and lemon wedges, if desired.
HOW TO REHEAT CRAB LEGS:
Crab legs are typically sold already cooked, so reheat instructions are the same as the original cooking instructions. I would not recommend reheating them more than one time, though, because they will become rubbery.