Confrontational option: tell your husband that only one person has the lived experience of growing up female and realising the social expectations of girls are narrower than they are for boys, and it's not him.
Tell him you are a feminist and you do not want to medicalise a girl to fit his sexist, misogynist boxes, you want to support her to be herself, despite her father.
More conciliatory option:
once upon a time I had a trans friend. I will not give their sex, because it should be immaterial. I will call them Quinn, for the purposes of this anecdote. One day, a mutual friend was showing off to Quinn about how trans-inclusive he was, and he said to Quinn, "if my kid was trans I wouldn't care and I'd support them with it all".
Quinn hit the roof
Quinn went through the financial costs of their planned surgeries, the psychological impact of experiencing gender dysphoria, the recovery from surgery, the possible risks of surgery (you have a risk of dying every time you go under general anaesthetic, the risk of irreparable nerve damage) and on and on.
Then Quinn told our friend that if they ever had a child and that child said they were trans, Quinn would take that child round every therapist Quinn could, to work out if their child to feel peace with their body without having a single operation.
The medical transition pathway is a shit path. Did you know that there is a 30% of longterm constant pain for women who have mastectomies? That risk is one thing when you have cancer and the only other option is dying of cancer. It's quite another thing when you're having a mastectomy as an elective procedure as a teenager.