Rebinding menu

Unity Engine
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1

Hey guys! I am using the new input system to move my character and want to create a rebinding menu, but I see that I cannot leave the field with my key empty by clicking on an empty space on the canvas, I have an LBM assigned to the action. Moreover, when I try to assign a space to an action, the button for rebinding is pressed again. because of this, I cannot assign a space for example for a jump. And I have two questions: the first is how to fix it and the second is how to make an empty action field. And finally, how do I make it so that I can’t assign the same key for different actions, say for jumping and moving forward. Thank you very much in advance