The APA strongly opposes conversion therapy (https://www.psychiatry.org/newsroom/news-releases/apa-reiterates-strong-opposition-to-conversion-therapy) "efforts to do so represent a significant risk of harm by subjecting individuals to forms of treatment which have not been scientifically validated and by undermining self-esteem when sexual orientation fails to change."
Teaching kids that they are wrong and need to be 'fixed' for something that doesn't need fixing causes irreparable harm to their mental health. In no way should this form of child abuse be legal just because some parents are bigots.