Airpods( Third generation connection Problem)

I bought Airpods third generation(Version 5E135) 3-4 months ago. Suddenly my right Airpod stopped working. so I forgot the AirPods to reset and tried to pair them again with iPhone 14 pro max (IOS 16.6.1). but I am unable to connect with my iPhone as the AirPods animation does not appear on my iPhone. However, I tried several options of turning off blue tooth again and again as well as switching off the phone. but still, I am unable to connect. what could be the problem? Any solution would be appreciated.