How do I add force to a RigidBody2D?

So I have this scene, where I have a player that can shoot bullets at an enemy. I want to AddForce to the RigidBody2D of the enemy when the bullet hits, but until now I have no success.
My bullet script:

 void Update()
{
    theRB.velocity = transform.right * speed;
}

private void OnTriggerEnter2D(Collider2D other)
{
    Instantiate(impactEffect, transform.position, transform.rotation);
    Destroy(gameObject);

    if (other.tag == "Enemy")
    {
       other.GetComponent<EnemyHealthController>().DamageEnemy(damageToGive);
    }

}

Where do I put the Addforce function? Do I have to get a reference from the enemy RigidBody on my Bullet Script?
I’m kinda new to unity so any help is much appreciated!
Thanks in advance.
PS: I’m trying to make to a topdown shooter game.

Adding impactforce on collision is part of the unity engine so you won’t have to script anything. But since you’re using the OnTrigger function im assuming that either the enemy or the bullet is a trigger in which case there won’t be a collision. you can simply use the OnCollision function instead

other is your enemy reference. So to add force to it it would right after line 13, you would add other.GetComponant().AddForce(theRB.velocity); to add the force of the bullet to the enemy.