Identifying the authenticity of a course can help to identify the authenticity by investigating the background of the course institution or company. If it is possible to be true, the institutional background is fine. Online education or technical courses can be enrolled. This name and phone number are left for the convenience of recording and sending you course information in the future. Of course, it is also convenient to promote you in the future. It won't be unsafe, but you should be prepared for harassment and promotion.