Acording to the qualifying process:
a. NOCs with no male or female qualified athlete or relay team will be allowed to enter their best ranked
male athlete or their best ranked female athlete in one athletic event, with the exception of the
Combined Events, 10,000m and 3000m Steeplechase.
b. This applies equally to unqualified female entries from an NOC with qualified males, and vice versa.
So if you have no one qualified, you get only a quota. But if you have only one gender represented, you get one for the other.