PX4-ROS 2 node for Custom node, Error Waiting for FMU

Hello all, I am trying to simulate this example I found here and run the ros2 custom node bu unfortunatelly when I run this command: ros2 run custom_mode custom_mode
I always get that error:
[DEBUG] [1750956880.500737390] [CustomMode]: Waiting for FMU…

[DEBUG] [1750956895.504119002] [CustomMode]: timeout while waiting for FMU

terminate called after throwing an instance of ‘std::runtime_error’

what(): Registration failed

Everything else works as they should, I have followed every step exactly as described.
Can you share your insights?