Ask for help单元问题:无法添加到 Google 课堂

Dear WISE design team, Thank you very much for developing WISE platform, which is very valuable and provides great support for daily teaching and learning. I am currently learning to use WISE platform, but I encountered a problem during operation. I hope I can get your advice. When adding activities and steps, there will be no serial number, as shown in the following figure. I really want to solve the current serial number problem. I will be very grateful if you can help me solve this problem.

Best wishes. I look forward to your reply.
Your loyal users.