This is your "long-range jab." A solid teep to the midsection keeps a charging attacker back and creates space for you to run.
To make your kickboxing functional for self-defense, incorporate these drills: Combat kick boxing : realistic self defence
If you end up on the ground, use your up-kicks to keep the attacker away while you perform a technical stand-up to get back to your feet safely. This is your "long-range jab