Scriptable tile

Trying to follow some tutorials and create a scriptable tile for the Tilemap system, I created a script with some public variables, when I use GetTile() I manage to get a reference to the scriptable tile, but I'm unable to access those public variable, why can't I access the three public variables in this script?

 #if UNITY_EDITOR
 using UnityEditor;
 #endif
 
 namespace UnityEngine.Tilemaps
 {
     public enum GroundType { Grass, GrassWet, Metal, Wood, Sand}
 
     public class GroundTile : Tile
     {
         public Sprite tileSprite;
         public GroundType groundType;
         public int layer;
 
         public override void GetTileData(Vector3Int location, ITilemap tileMap, ref TileData tileData)
         {
             base.GetTileData(location, tileMap, ref tileData);
             {
                 tileData.sprite = tileSprite;
                 tileData.colliderType = Tile.ColliderType.Sprite;
             }
         }
 
 #if UNITY_EDITOR
         [MenuItem("Assets/Create/Ground Tile")]
         public static void CreateGroundTile()
         {
             string path = EditorUtility.SaveFilePanelInProject("Save Ground Tile", "New Ground Tile", "asset", "Save Ground Tile", "Assets");
             if (path == "")
                 return;
             AssetDatabase.CreateAsset(ScriptableObject.CreateInstance<GroundTile>(), path);
         }
 #endif
     }
 
 #if UNITY_EDITOR
     [CustomEditor(typeof(GroundTile))]
     public class GroundTileEditor : Editor
     {
         public GroundTile tile { get { return (target as GroundTile); } }
 
         public override void OnInspectorGUI()
         {
             EditorGUI.BeginChangeCheck();
             tile.tileSprite = (Sprite)EditorGUILayout.ObjectField("Sprite", tile.tileSprite, typeof(Sprite), false);
             tile.groundType = (GroundType)EditorGUILayout.EnumPopup("Ground Type", tile.groundType);
             tile.layer = EditorGUILayout.LayerField("Layer", tile.layer);
             if (EditorGUI.EndChangeCheck())
                 EditorUtility.SetDirty(tile);
         }
 #endif
 }

This prints: MyTile (UnityEngine.Tilemaps.GroundTile)

 Tilemap tileMap = collider.GetComponent<Tilemap>();
 TileBase currentTile = tileMap.GetTile(tileMap.WorldToCell(collisionPos));
 print(currentTile);

Now that I have a reference to my custom tile, how do I get those public variables?