How to make a character move around randomly?

Unity Engine
1

I have a very simple horror game where there is an enemy. If you get into his radius, he will follow you. But if you aren’t, he doesn’t do anything. I find that boring and was thinking of ways to make him move around randomly. But I couldn’t think of anything. Here is the code that makes the enemy move in the first place:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;

public class Walker : MonoBehaviour
{

    public float lookRadius = 10f;

    NavMeshAgent agent;
    Transform target;

    void Start()
    {
        target = PlayerManager.instance.player.transform;
        agent = GetComponent<NavMeshAgent>();
    }

    void Update()
    {
        float distance = Vector3.Distance(target.position, transform.position);

        if(distance <= lookRadius)
        {
            agent.SetDestination(target.position);
        }
    }

    void OnDrawGizmosSelected()
    {
        Gizmos.color = Color.red;
        Gizmos.DrawWireSphere(transform.position, lookRadius);
    }
}

What do I add so the character moves around randomly?

2

Give them a random destination when they’re not within distance of the target? Picking a random location might be difficult depending on how your game’s world is setup. Perhaps they should patrol a certain path instead?