How do I unlock my MacBook Pro's locked keypad?

Try restarting your MacBook Pro by holding down the power button until it shuts off completely, then turn it back on. If that doesn't work, you may need to visit an Apple Store or contact Apple Support for further assistance.

Can you try Ann external wired keyboard to log in?

make certain that:

Settings > Accessibility > Keyboard > Full keyboard access is set OFF

"Full keyboard access" should be read as 'Use All keyboard, NO mouse'

or possibly this:

If a numeric keypad doesn’t work on Mac - Apple Support