Is it true that the "forbidden tree" in the Holy Qur’an means sexual intercourse between male and female, and that "Adhan Al-An’am" is a book that contains what contradicts the creed?

The interpretation of the forbidden tree mentioned in the question is false and not reported by the people of knowledge. The specific tree that Allah forbade Adam and his wife has not been definitively identified by evidence from the Qur'an or authentic Sunnah. Rather, there are reports from some of the Tabi'in regarding its identification, most of which are transmitted from the People of the Book. It has been said to be the fig tree, or the grape vine, or wheat. The correct view is not to specify it, because Allah did not provide evidence for that, and knowing it does not benefit, while being ignorant of it does not harm.