Grab action doesnt work!

[BlackJ36]

Is there a mistake of the action space "grab" , the description in the document seem to be wrong?
bool. If True and the agent is holding an object, grab the object at the center of the image. If True and not holding, put the object on the surface at the center of the image

I make sure the object is in the centre of the simulator,and grab() function output correctly.Howerver, it doesnt work.

There are more question I hope you can give me some tips:
How can I control the robot Directly?
How can I input my instruction without typing in the client？Such as udp or other way.

Thanks for your excellent work,I hope to get your help as soon as possible!!!