According to the website of TransAthlete, most of the laws that US states have passed to address the thorny issue of "trans inclusion" in school sports either don't mention "female to male trans students" at all, or offer them considerable latitude to do as they wish.
24 individual US states have passed bills restricting "trans inclusion" in sex-segregated school sports in HS and lower grade levels - but most of them are aimed solely or primarily at limiting the incursion of male athletes into female sports.
More than half the bills - 13 - are totally silent on whether female students who claim to be trans - or have adopted another special gender identity at odds with their sex - can compete on boys' teams.
Seven of the bills say that female students who identify as/claim a trans identity can go out for boys' HS sports, and they are free to compete in them if they can make the team.
Four states ban girls from boys' HS sports, but only in schools that offer a girls' team/program in that same sport.
I haven't looked at each state law separately, but the laws that allow females to go out for male sports based on gender identity or any other reason probably include some fine print and caveats limiting or totally prohibiting female athletes - regardless of their identities - from boys' HS sports in those particular sports where playing on a boys' team in HS and competing against male HS students would put female athletes at undue risk of physical injury or death.
Just as there's now much more awareness than in the past about the alarming risks of longterm brain damage from concussion that male athletes face in American football and ice hockey, there's now much more attention paid to the fact that due to differences in head, neck and shoulder anatomy, female athletes are much more likely to incur concussion, whiplash and serious neck injuries, and to suffer longterm brain damage from such injuries, than males are. As a result, regulations and style of play are changing in female sports like girls' and women's soccer and volleyball so as to lower the risk of these types of injuries.