Turn on a multi-functional pressure cooker (such as Instant Pot) and select manual function. Place the trivet in the pot and add water. Place wings on the trivet. Close and lock the lid and seal the vent. Select high pressure according to manufacturer's instructions; set the timer for 12 minutes. Allow 20 to 25 minutes for pressure to build.
Release pressure carefully using the quick-release method according to manufacturer's instructions, about 5 minutes. Unlock and remove the lid.
Set an oven rack about 6 inches from the heat source and preheat the oven's broiler. Line a jelly roll pan with aluminum foil.
Remove wings from the pressure cooker and pat dry with paper towels. Mix barbecue sauce and melted butter together in a bowl. Place wings on the prepared pan and baste with barbecue sauce mixture.
Cook wings under the hot broiler, turning once, until desired crispness is reached, 5 to 15 minutes.