If you have printed the lifter for the AMS Pro 2 for the P1/P2 or H series Bambu printers (which I would recommend) and the front handle accessory and if you have less than a full complement of filaments in the AMS unit, the unit will not stay upright because the center of gravity is too far forward.  This model is designed to be inserted into the right side of the AMS base with its supporting cylinders facing outward.  Then, you can lower the unit slightly to rest on the right edge of the printer with the top glass removed to allow access without risk of crashing down.