Enable and toggle through Render Modes in Godot 4.x

DebugRenderMode.gd

# Taken from TokisanGames: https://www.reddit.com/r/godot/comments/d459x2/finally_figured_out_how_to_enable_wireframes_in/
# There is a total of 25 draw modes at the time of this, for further information take a look at the ViewportDebugDraw-Enum:
# I found the first 5 to be worth using.
# https://docs.godotengine.org/en/stable/classes/class_renderingserver.html#enum-renderingserver-viewportdebugdraw

extends Node

@onready var vp = get_viewport()

func _ready() -> void:
	RenderingServer.set_debug_generate_wireframes(true)

func _input(event):
	if event is InputEventKey and Input.is_key_pressed(KEY_P):
		vp.debug_draw = (vp.debug_draw + 1 ) % 6