special keys to increase volume on my macbook air m2 does not work how to fix it

Hey there and welcome to Apple Support Communities kaushalfromargenteuil,

We can certainly understand your concern and can help provide some insight.

We recommend checking out these steps for more information on how to use the function keys on your keyboard and see if that matches up with your procedure.

" How to use the function keys on your Mac

The top row of keys on your Apple keyboard can control built-in Mac features or be used as standard function keys.

Use the keys to control features

By default, the top row of keys on your Apple keyboard control many different features on your Mac. For example, pressing the keys with speaker icons adjusts the volume.

If your Mac has a Touch Bar, learn about using function keys on MacBook Pro with Touch Bar.

Use the keys as standard function keys

Press and hold the Function (Fn)/Globe key  while pressing a function key. For example, pressing both Fn and F12 (speaker icon) performs the action assigned to the F12 key instead of raising the volume of your speakers.1 If your keyboard doesn’t have an Fn key, try pressing and holding the Control key when pressing a function key.

Change the default behavior of the keys

If you want to change the top row of keys to work as standard function keys without holding the Fn key, follow these steps, depending on the version of macOS you're using:

macOS Ventura

1. Choose Apple menu  > System Settings.
2. Click Keyboard in the sidebar.
3. Click the Keyboard Shortcuts button on the right.
4. Click Function Keys in the sidebar.
5. Turn on “Use F1, F2, etc. keys as standard function keys”.

Earlier macOS versions

1. Choose Apple menu  > System Preferences.
2. Click Keyboard.
3. Select “Use F1, F2, etc. keys as standard function keys”. "

For additional information, check out this link: How to use the function keys on your Mac - Apple Support

These steps will help ensure your device is working with ease and can fix common issues like the ones you’re experiencing.

Kindest regards!