If you buy the book of Shanxiang Education, you can watch the corresponding online class on Shanxiang Education APP by the following steps:

1. Open the Shanxiang Education APP and log in.

2. Click on the "My" option, and then select "My Course".

Here you can find the courses related to the books you bought, and you can study according to the course time.

If you have any questions about Shanxiang Education, I suggest you check Shanxiang Education official website or contact their customer service team for more information.