You have 3 options that you can choose for this use case:
Use our random number generator extension. It allows you to generate alphanumeric numbers as well.
Use Autonumber field
Use Record ID
QR Code Generator on Airtable
You have 3 options that you can choose for this use case:
Use our random number generator extension. It allows you to generate alphanumeric numbers as well.
Use Autonumber field
Use Record ID