Add this line below your StateDef:
[State 300, VelSet]
type = VelSet
trigger1 = 1
x = X ; Where X is an int. Change X according to your preference
y = 0
Or if you want the movement of your character to be in pixels, add this below type = A
velset = X, 0 ; Again X is an int, change this number according to your preference.
Hope this helps.