HI cvetan163, welcome to the Apple community
I hope you are doing well 🤗
Normally the update of AirPods is automatic and can not be done manually. If you notice that your AirPods are not updated, I invite you to reset them and wait a few days to see if the update is done. If the update still doesn't happen, it's possible that the AirPods are fake, because it's not possible to update fake AirPods. If your AirPods are real, but you still can't update them, I invite you to contact Apple support.
I invite you to try this :
1/ Put your AirPods in their charging case, and close the lid.
2/ Wait 30 seconds.
3/ Open the lid of your charging case.
4/ With your AirPods in your ears and connected to your iPhone, iPad, or iPod touch, go to Settings > Bluetooth, or Settings > [your AirPods], and tap the More Info button next to your AirPods. If you don't see your AirPods in Settings > Bluetooth or in Settings > [your AirPods], just go to the next step.
5/ Tap Forget This Device, and tap again to confirm.
6/ With the lid open, press and hold the setup button on the back of the case for about 15 seconds, until the status light on the front of the case flashes amber, then white.*
7/ Reconnect your AirPods: With your AirPods in their charging case and the lid open, place your AirPods close to your iPhone, iPad, or iPod touch. Follow the steps on your device's screen.
-How to reset your AirPods and AirPods Pro - Apple Support
If the issue is not resolved, feel free to come back to us or contact Apple support for more information.
Apple support is available here: Apple Support
See you soon👋
Julio