Cut your lobster tails in half (if needed).
Pour water in the Instant Pot and place the trivet.
Place the lobster tails onto the trivet (shell down). If your Instant Pot is not big enough, you can cook in batches.
Cook at low pressure for 3 minutes or 4 if your lobster is frozen.
In the meantime, melt butter in a saucepan and add garlic, lemon juice, salt and pepper to obtain a sauce.
When cooking time is over, do a quick pressure release and serve the lobster tails topped with the prepared butter sauce and lemon wedges to taste.