What is the function of the Audi 80 transmission lock button?

I know that the Audi 80 comes with a transmission lock button, but I'm not sure what it does. Can someone explain its purpose and when to use it?

The Audi 80 transmission lock button is designed to prevent the transmission from shifting out of a specific gear, typically used for towing or climbing steep hills. It's important to read your vehicle's manual for specific instructions on when to use it.