The capacity of the elevators is set in the properties of the elevator bank. It consists of three values: the "Elevator Capacity" as a dimensionless number and the "Traveler Capacity Usage", which determines how much capacity each traveler takes up.
The resulting number of possible travelers (43 with the given value/option/traveler size) is then also bounded by the "Max Entries/Exits" value.

In your model, the people wait in a line until they can acquire a location resource. Only after they acquire a location do they start to move to a different floor. This is what restricts how many people enter the elevators at model start.