Manual

Add a boolean to keep track of the light state:
class TurtleBot4FirstNode(Node):
lights_on_ = False
def __init__(self):
And modify button_1_function to toggle the light:
# Perform a function when Button 1 is pressed
def button_1_function(self):
# Create a ROS2 message
lightring_msg = LightringLeds()
# Stamp the message with the current time
lightring_msg.header.stamp = self.get_clock().now().to_msg()
# Lights are currently off
if not self.lights_on_:
# Override system lights
lightring_msg.override_system = True
# LED 0
lightring_msg.leds[0].red = 255
lightring_msg.leds[0].blue = 0
lightring_msg.leds[0].green = 0
# LED 1
lightring_msg.leds[1].red = 0
lightring_msg.leds[1].blue = 255
lightring_msg.leds[1].green = 0
# LED 2
lightring_msg.leds[2].red = 0
lightring_msg.leds[2].blue = 0
lightring_msg.leds[2].green = 255
# LED 3
lightring_msg.leds[3].red = 255
lightring_msg.leds[3].blue = 255
lightring_msg.leds[3].green = 0
# LED 4
lightring_msg.leds[4].red = 255