Step1: Log in to https://edu.aliyun.com/certification , select the certification exam you need to take and enter the details page. In the "Exam Appointment" position on the details page, select the PROMETRIC exam center and click "Register". (The following takes cloud computing ACP certification as an example)
Step2: After clicking registration, fill in the registration information according to your personal situation. Fill in the ACP certification authorization code obtained from the teacher in the authorization code position. (Contact the teacher at the bottom to purchase the authorization code, there will be a discount, and there will be supporting test preparation materials)
Step 3: After completing the filling, click Submit. If the information is correct, it will prompt that the registration is successful. Just see "Registration Successful" and there is no need to make an appointment here.
Step4 (this step is very important):
1) Check the registered qualification code: https://edu.aliyun.com/clouder/my/clouderpackage?type=acp
2) Check the registered Alibaba Cloud account ID:
https:// account.console.aliyun.com/v2/#/basic-info/index 
3) Prepare the above qualification code + account ID + name, contact the teacher on WeChat at the bottom, he will arrange an online examination room for you
Step 5: Prometric staff will send a confirmation letter to the candidate's email based on the registration information. The candidate will be prompted to install the corresponding software according to the content of the confirmation letter. Staff will contact you to arrange the online exam before the exam.
Reference link: https://mp.weixin.qq.com/s/TkuSF3HeDaVvs2mlzofo9Q
Appendix 1: Prometric Online Exam User Manual:
https://www.prometric.com.cn/download/PrometricProUserGuide_CHS.pdf
Prepare a computer with a camera and download the exam software in advance: ProProctorSetup.exe
Appendix 2: Prometric offline exam time inquiry link: https://proscheduler.prometric.com/?prg=actc&culture=zh-CN&path=seatavail