Dear sir or madam,
The reason for writing this email is to hope that you can respond to my request as soon as possible. I sent you an email on September 1 （发送上封邮件的日期）(subject: Request to get my system registration email（上封邮件的主题，要完整呈现）), maybe you missed my email, There was no response to my request.
I hope you can send the registration email to my mailbox as soon as possible（提供解决方案）, the course start date is approaching, if I am late to complete the registration, I will not be able to take the course.
Looking forward to your reply!
Best Regards
Zhang Shan