where is this key slot I need to find it oplease help
There is no slot in the center console or anywhere really. That "slot" is behind the round plastic on the steering column, usually it would be pried off but for some reason the Fiestas don't have this. They have a sort of RFID/sensor system.
Hold the key fob up to the circle on the right side of the steering column where you would usually insert a key. Place the flat end of the key fob in the center and step on the clutch and press the start button. If this doesn't work try rotating the fob a bit as so it catches the sensors. Still not working remove the battery cables wait 30 min for a reset and try to start the car again. Still not working and you have attempted all of the above and checked/replaced Key Fob battery call Ford. Probably will have to reprogram the fob or get a new fob.
Source of knowledge: working at a dealership.