basic interface and no success trying to use them in a Tool script

scenes/enemies/FirstEnemy.cs

@@ -2,7 +2,9 @@ using Godot;
 using System;
 using Movementtests.player_controller.Scripts;
 
-public partial class FirstEnemy : CharacterBody3D
+
+[GlobalClass]
+public partial class FirstEnemy : CharacterBody3D, ISpawnable
 {
 	[Export]
 	public Node3D Target { get; set; }
@@ -17,6 +19,16 @@ public partial class FirstEnemy : CharacterBody3D
 		_wallInFrontRayCast = GetNode<RayCast3D>("WallInFrontRayCast");
 	}
 
+	public Resource GetSpawnInitResource()
+	{
+		return Inputs;
+	}
+
+	public void TestMethod()
+	{
+		GD.Print("I'm an enemy");
+	}
+
 	public override void _PhysicsProcess(double delta)
 	{
 		var target = Target.GlobalPosition;