My AIR PIX prop popped off, how do I put it back on?

If you should lose a propeller, please know that there are 2 types of propellers; A & B props. The upper left and lower right are B props.  Upper right and lower left are A props.  The A or B can be found near the center of each propeller.  The replacement props are in a small plastic bag and are in the same compartment in the AIR PIX box that has the USB-C cable.