water is leaking under the dash
When does it happen? It could be a clogged ac drain or it could be a leaking windshield seal or something else completely.
You have water condensing in the box that holds your heater and A/C system in any mode the uses A?C or defrost. It collects in a tray that drains to the ground via a rubber tube in the engine compartment. If that tube is plugged, waster will spill over under your dash on the passenger side.
The usual way to clear it is with air from a conpressor from the bottom of the tube or with string trimmer line worked up the tube, be gentle, you don’t want to puncture the tube.
You could have leaking coolant from the heater core but that would smell sweet in an unpleasant way. It would also leave an oily film on the inside of your windshield.
You could also have a windshield leak but that would only happen in the rain or a car wash.