WiFi App on Legato FW16?

For a number of reasons I am unfortunately forced to use version 13 of the Legato FW. I have a serious problem getting the WiFi to work (which I didn’t have for example in version 20). In fact, in version 20, the WiFiService with its API is included, which instead appears to be absent in previous versions. In fact I get an error that says that the system obviously does not find WiFiService. Do you happen to know how to incorporate these APIs into a project and how to make WiFi work on a version like 13 in general? Any help will be appreciated, thanks to all