Is “Liang Zhongshu, the Defender of Daming Prefecture, extorted a hundred thousand strings of gold, pearls, and treasures as a birthday gift, which was robbed by Chao Gai and others at Huangni Ridge.” true?

Historically, there was indeed a Defender of Daming Prefecture named Liang Zimei (the prototype of Liang Zhongshu in the novel), who was indeed the son-in-law of the powerful minister Cai Jing, and had a record of presenting rare treasures to the court. However, there is no record in the History of Song that Liang Zimei extorted a huge fortune of a hundred thousand strings as a personal birthday gift (the Birthday Convoy) and was robbed by a group of outlaws at Huangni Ridge. Although the story of 'Outsmarting the Birthday Convoy' is widely known, it is entirely a fictional masterpiece created by the novelist to introduce the gathering of heroes at Liangshan.