Forgot my mac 4 digit pass

Are you looking for your Mac user account?, that is your login user name to your MacBook Air.

See the following Apple articles:

If you forgot your Mac login password -> https://support.apple.com/en-us/HT202860

Change the login password on Mac -> https://support.apple.com/en-gb/guide/mac-help/mchlp1550/mac

Reset your Mac login password -> https://support.apple.com/en-mn/guide/mac-help/mh35902/mac

If you can't reset your Mac login password -> https://support.apple.com/en-gb/HT212190

With pleasure to be able to help you.

Thank you for your feedback and you're welcome.