Godot 4 method to screenshot at resource path viewport with or without transparent background.

screenshot_viewport.gd

func screenshot_viewport(transparent_background: bool = false) -> void:
	var time_string: String = Time.get_datetime_string_from_system().replace(":", "-").replace("T", "-")
	var path := "res://screenshot-" + time_string + '-' + str(randi() % 8999 + 1000) + ".png"
	var viewport := get_viewport()
	
	if transparent_background:
		viewport.transparent_bg = true;
		await RenderingServer.frame_post_draw

	var error: Error = viewport.get_texture().get_image().save_png(path)
	
	if transparent_background:
		viewport.transparent_bg = false;
	
	if !error:
		print("Screenshot saved: ", path)