There is usually a release next to the gear shifter. It will be covered over with a piece of plastic on the console, usually about a half inch wide and has a place to stick a flathead screw driver. Pry the plastic piece off and use the end of the screw driver to release the mechanical lock. Then be sure the shifter is adjusted properly as this will cause the button not to be able to release the park lock.
Otherwise, check the brake light fuse which needs to be working to power the lock release with the brake pedal.
Check the fuse first, but if you need to drive you can pop that cover off and unlock manually.
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Frank