I accidentally forgot a device on bluetooth(my AirPods) how can I reconnect them again?

Howdy,

I just tested and this works, from Use AirPods with your Mac

1. With your AirPods in their case, open the lid.
2. Press and hold the setup button on the back of the case until the status light flashes white.
3. On your Mac, choose Apple menu > System Preferences, then click Bluetooth.
4. Select AirPods in the Devices list.

Pressing the little round button on the back of the case puts the AirPods in discovery mode.

ivan