This is outright ageism.
I'm a 47 year old man. What if I identify as a 10 year old girl? Shouldn't I be allowed to join the Girl Scouts and sell cookies too?
men over the age of 18 are welcome to join Girl Scouts as adult members
many Dads do, many troops have cookie Dads
If you want to work with the kids as a volunteer however you have to undergo a background check. You will not lead a troop unless you have an unrelated female leader assistant
Hope this answers your concerns about sexism and ageism