Enable/disable input for the whole game/app

enable_disable_input.gd

func disable_input(actions_allowed = []) -> void:
	for action in InputMap.get_actions():
		# Allow some input actions.
		if action in actions_allowed:
			continue

		# Remove the action and its events.
		InputMap.action_erase_events(action)
		InputMap.erase_action(action)
		# To avoid the error: The InputMap action "xxx" doesn't exist.
		InputMap.add_action(action)


func enable_input() -> void:
	InputMap.load_from_globals()

Example of allowing some input actions:

disable_input(["ui_accept", "ui_cancel"])