The “gender pay gap” absolutely does exist, look up any results from any census ever. Even the myriad ways of “explaining it away” which you can find on the Wikipedia page [1] cannot fully account for the gap (regardless of whether these explanations are valid/fair/equitable or not). Where exactly are you reading that the gender pay gap does not exist?

[1] https://en.wikipedia.org/wiki/Gender_pay_gap_in_the_United_S...