Should the materials of library courses be bought in official website or JD? COM？

Official website is safer.

Library course is a professional online education platform launched by Tencent. A large number of high-quality educational institutions and famous teachers have gathered, including vocational training, civil service examination, TOEFL IELTS, research grading, oral English, primary and secondary education coverage, teacher qualification certificate, teacher recruitment, special edition, special edition, special edition and many other online learning quality courses.