Resets an Unity tilemap

MapReset.cs

using UnityEngine;

namespace Scripts
{
    public class MapReset : MonoBehaviour
    {
        public Terrain terrain;
        private float[,] originalHeights;
     
        private void OnApplicationQuit() {
            this.terrain.terrainData.SetHeights(0, 0, this.originalHeights);   
        }
     
        private void Start()
        {
            this.originalHeights = this.terrain.terrainData.GetHeights(
                0, 0, this.terrain.terrainData.heightmapResolution, this.terrain.terrainData.heightmapResolution);
        }
    }
}