In the inner pot of a 6-quart or larger instant pot, whisk together the chili sauce, apricot preserves, barbecue sauce, water, red pepper flakes, granulated onion and garlic until smooth. Stir in the frozen meatballs and then lock the lid in place, making sure the valve is set to seal. Pressure cook on high for 6 minutes, and then release the pressure carefully using the quick-release method according to manufacturer's instructions, about 5 minutes. Unlock and carefully remove the lid.
Give the meatballs a stir and transfer to a large serving bowl. Garnish with chives or scallions before serving.