How do I stop enemy AI from bumping and entering into my player?

Hey,
I am trying to stop the AI enemy from bumping into my player and staying at a distance but unable to do so. can you please help me out??
I have colliders attached on both but trigger is off.

I am attaching the script which i am using for the enemy ai to chase my player

using UnityEngine;

public class KeepDistance : MonoBehaviour
{
    public Transform player;
    public float desiredDistance;

    private void Update()
    {
        var offset  = this.transform.position - player.position;
        if (offset.sqrMagnitude < desiredDistance * desiredDistance)
            this.transform.position = this.transform.position + offset.normalized * (desiredDistance - offset.magnitude);
    }
}

This will keep an object at the desired distance to another object.