Soak 8 to 10 wooden skewers in water for at least 30 minutes.
Thread skewers with chicken, pineapple and bell peppers and red onion, alternating ingredients evenly.
Brush skewers with olive oil and season with salt and pepper.
Select preset program of Preheat to preheat air fryer.
Working in batches, place half the skewers in the air fryer.
Select Preheat program again, and set temperature to 400°F/200°C and time to 12 to 14 minutes, then press Start/Stop to cook until fully cooked. Repeat with remaining skewers.
Meanwhile, combine remaining ingredients in a small saucepan over medium heat. Simmer until sauce thickens, about 5 minutes.
Brush sauce over skewers and serve.
Tip: Leftover sauce can be refrigerated in an airtight container for up to 1 week.