The A5 shotgun features a bolt latch mounted just forward of the trigger guard, on the bottom of the shotgun.  The bolt latch performs two functions:

Allows the slide assembly to be locked in the open position when the magazine is unloaded.

Releases a shell from the magazine to be loaded into the chamber.

The bolt latch must be slid rearward before pulling the operating handle completely rearward in order to lock the slide assembly in the open position or release a shell from the magazine to be chambered.