Pour 1 cup water into the Instant Pot inner pot. Place the trivet inside and arrange the 32 oz frozen meatballs on the trivet. Close the lid, set the steam release valve to SEALING, and cook on High Pressure for 5 minutes.

When the cook time ends, perform a Quick Release of the pressure. Open the lid away from your face. Carefully lift out the trivet and transfer the meatballs to a colander or bowl to drain; cover to keep warm.

Pour out and discard the cooking liquid from the inner pot. Wipe the inner pot bottom if there is any large residue.

Add 2 1/2 cups grape jelly and the 12 oz bottle of chili sauce to the empty inner pot. Select Sauté (Normal/Medium) and whisk the jelly and chili sauce together until smooth, about 3–5 minutes, scraping the bottom to prevent burning.

Return the drained meatballs to the pot and stir gently to coat them evenly with the sauce. Sauté for 2–3 minutes more so the meatballs are heated through and the sauce thickens to a glaze.

Turn the Instant Pot off or set to Keep Warm. Serve the glazed meatballs.