jump player by script

Unity Engine
1

Hi, I would like that when the player touched a trigger (with tag = jump) then the player would move on the Y axis to simulate precisely the jump.
How can I accomplish this?

2 
void OnTriggerEnter(Collider col){
if (col.CompareTag("jump"))
allowYMovement = true;
}
}

void Update(){
if (allowYMovement)
///apply y movement here.

else{
///no y movement
}
}