Can't get data from Gazebo to Simulink

I have connected Simulink to Gazebo and I can send the velocities to the quadrotor without problems, but, BUT I can not receive the real data from the drone; when I connect a scope block to the subscribe block, the "Z position" signal for example remains at zero even if the drone is changing position ! same thing for other coordinates.

[Chawki CRTL]

I resolved my problem by following the steps 1 ---> 6 described in the link below: https://fr.mathworks.com/matlabcentral/answers/196911-use-matlab-robotics-system-toolbox-to-receive-ros-message