Gazebo simulation doesn't takeoff

I followed instructions from this link Gazebo Simulation | PX4 User Guide. The gazebo and PX4 can start but I don’t see “commencing GPS fusion” and the drone doesn’t takeoff when I commander takeoff.
The terminal script is below. How should I solve it? Thanks!

@Zxr1230 As you can see in the log, the no datalink failsafe is being triggered.

This meana you dont have a ground software open (QGroundcontrol)

Thank you! How should I connect it to the QGroundcontrol? I installed QGroundcontrol on the same computer as the gazebo. Is there an instruction?