It can be generated from LLF tab at Story Settings.

The effective seismic weight, W, of a structure should include the dead load and a minimum of 25% of the floor live load.

If a building sways during an earthquake, only that portion of the mass or weight that is physically tied to the structure needs to be considered as effective. Also certain types of live loads, such as storage loads, may develop inertial forces, particularly where they are densely packed.