Determine fundamental natural time period of building in ETABS with reference to BNBC-2020- Seismic

Assalamu alaikum,
Hello guys,
In this tutorial, I will show you how to determine the fundamental period of vibration of a building structure. Fundamental period of a building structure is defined as the period of mode of vibration in which the building oscillates to and fro in a single mode. The lowest frequency of the structure is the fundamental frequency. We need this data to perform equivalent static analysis to determine the earthquake lateral load.
According to BNBC-2020, Structural dynamics procedures (such as Rayleigh method or modal eigenvalue analysis) may be used to determine the
fundamental period T of the building in the direction under
consideration. This period shall not exceed the approximate
fundamental period by more than 40 percent.
(b) The building period T (in sec) may be approximated by the following, T=0.0466h^0.9 (Concrete moment resisting frames).
h=Height from base to top of the building, m

According to BNBC-2020,
Seismic weight:

Seismic weight, W, is the total dead load of a building or a structure,
including partition walls, and applicable portions of other imposed loads listed
below:
(a) For live load up to and including 3 kN/m2, a minimum of 25 percent
of the live load shall be applicable.
(b) For live load above 3 kN/m2, a minimum of 50 percent of the live load
shall be applicable.
(c) Total weight (100 percent) of permanent heavy equipment or
retained liquid or any imposed load sustained in nature shall be
included.
Where the probable imposed loads (mass) at the time of earthquake are more
correctly assessed, the designer may go for higher percentage of live load