my macbook speakers are not available,

Check your sound settings

First, disconnect any cables from the USB, Thunderbolt, or 3.5mm audio ports on your Mac.

1. From the Apple menu , choose System Preferences.
2. Click Sound.
3. Click the Output tab, then select the built-in speakers. If you don’t see built-in speakers as an option in the Output window, contact Apple Support. 
4. If the Output volume slider is set low, move the slider to the right and test again.
5. If the Mute checkbox ✅ is selected, deselect it and test again.
6. If you still don’t hear any sound, contact Apple Support. 