Who invented the taiji diagram?

Chen Zhuan was a famous Taoist scholar in the early Song Dynasty. Legend has it that Chen Tuan met the fairy Lv Dongbin during the break. Lv Dongbin sent Chen Tuan a black and white photo. Lv Dongbin said it was handed down from the previous generation of immortals, and Chen Tuan carved this picture on the stone wall of Huashan Mountain, which is also the oldest Tai Chi picture. Some people think that the Taiji diagram was created by Fuxi, and the fish entangled in Yin and Yang are Fuxi and Nu Wa. The origin of taiji diagram has always been confusing.