Keyboard suddenly stopped working

This sounds like your system got wet from a liquid spill into the keyboard or the keyboard connection to the logic board is loose. But as you also lost your speakers which tells me the headphone jack also got wet so I'm really thinking liquid spill here.

If we look at the uppercase from the other side we can see there the logic board sits we have the keyboard just on the other side

The cable connection to the logic board for the keyboard and fan is marked in Orange.

So you could replace the upper case MacBook Pro 13" Retina (Touch Bar, Late 2016-2017) Upper Case to fix the keyboard. I would first try replacing the MacBook Pro 13" Retina (Touch Bar, Late 2016-2017) Headphone Jack as there are switches which send the signal to the speakers from here, so if this is damaged the speakers won't work.Then depending on the damage you can replace the Speakers