You can go in. The main reason why you can't log in is that your network is not good. Try to switch to another network. Of course, it is also possible that the server is not good, because the school website is not as well maintained as the server of a big company in official website.

The Central Radio and Television Technical Secondary School is a technical secondary school founded by the National Open University with the approval of the former State Education Commission. Its main responsibility is to be responsible for the overall coordination, guidance, service, evaluation and supervision of the teaching and teaching management of secondary vocational education within the national open system, and to recruit junior high school graduates and above and on-the-job youth to hold secondary vocational education through the national open system and cooperative schools. The school has the qualification to issue national education series secondary education graduation certificates.