I used the "Refresh SDK Components" button in the "Project Explorer". I then looked at the latest SDK documentation, which appears to only be available as a web resource, not a downloadable PDF. Unfortunately, I still don't see how to do GETs and PUTs using the LWIP library.
Do you add the SDK 2.7.0 in the installed SDKs?
Then you can import the official SDK again in your IDE.
About the document, you can refer to the project readme under project doc folder.
Then, you can check more details from the code and the SDK test result. From the readme, you can find this client project also support the write to server and read from server functions.