There are shown to be male mages in Wandering Witch: Journey of Elaina, and Elaina indicates that mage and witch denote rankings of magic users, with mages progressing into witches by taking the exam and then completing an apprenticeship with a witch. There would seem to be no reason a male mage couldn't become a witch, but is that the case in this world? I certainly didn't see any show up in the anime.
The term witch historically was not entirely exclusive to females (males were accused and executed during the Salem Witchcraft Trials, for instance), but in modern times witches are almost predominantly female, and is often used as the female equivalent of the male wizard, in spite of terms such as sorceress and wizardess existing that contain much less negative connotations. Some fantasy settings will, of course, make distinctions between all of these labels and have them mean different things, which can be quite cool. And there are some cases, such as the masterful manga Witch Hat Atelier, which do indeed have male witches.
So, what is the case in Wandering Witch?