here's one way:
u need counter
upon pressing button, if counter is 0: set counter to 2
upon pressing button, if counter is >0: set key x on
every 0.0.50 if counter >0: subtract 1 from counter
if key x is on: do whatever event u use to make him faster
You need to make a custom movement. Create a counter for the dash it should have a maximum of 3 and minimum of -3. It is a bit complicated to explain. i made one exmaple already which im turning it into a beatem up engine. It would be much easier over messenger. If you still want me to explain just say so, or give me your messenger name through private message