Hi,
I was following the guide for connecting to Google cloud service. I realized that there are some libraries need to be included. They are Seeed embedtls, Seeed FS, Seeed rcpUnified etc.
Thank you very much for your suggestions and feedback. We usually ask our users to prepare all the following libraries before using the WiFi function to ensure that the program compiles smoothly.
Okay, There it is. Then it is my mistake as I did not see the overview section.