Set Instant Pot to saute, more (or high) setting.
Add coconut oil and butter and allow to melt completely and start to sizzle (important step - watch video in this post for an example).
Add popcorn kernels and stir so all kernels are coated with oil.
Place glass lid on top and hold, popcorn will begin popping in about 2-3 minutes, turn off when 2/3 of kernels have popped and they will continue to pop but not burn.
Carefully remove lid. Pour out of pot when done so they don't continue to cook. Salt and you're done!