Is it permissible to continue supplicating for the sex of the fetus to be changed from female to male, knowing that I believe in Allah’s divine decree and destiny?

It is not permissible to go to a doctor merely to know the gender of the fetus, as this necessitates uncovering the awrah (private parts) without necessity. It also appears that it is not prescribed to supplicate for a change in the gender of the fetus once you have confirmed it is female, because this is considered an act of transgression in supplication.