Is it obligatory to go to the daily training location for salary analysis, knowing that the number of trainees is incomplete, there is no work to be done there, that the official has permitted non-attendance except upon contact, and that the other trainees do not adhere to daily attendance?

It is obligatory to fulfill the agreement with the employer by attending the workplace every day. If the manager is authorized by the employer to exempt you from attendance, then there is no objection, and the salary is lawful. However, if the manager does so without the employer's knowledge or authorization, then this is not permissible Islamically, and it does not allow you to be absent from work or receive the salary.