When you see the white light flash, that means your AirPods are reset and ready to connect to your other devices.
If you're having trouble with your AirPods, one of the first things you can try is resetting them. This process will erase all of your AirPod's settings and return them to their factory default state. If your AirPods aren't working properly, resetting them might fix the problem. Here's how to do it:
Open the lid of your AirPods case, then press and hold the button on the back for a few seconds. When you see the white light flash, that means your AirPods are reset and ready to connect to your other devices.