Is there an API for google-drive in C ++ / Qt OR Any tool, such as Insync, that is free to use and can be used to access and manage on a Google drive. I tried using qt-google-drive from ics, but it is still under development.
You can use Google Drive from anything that can generate HTTP requests (and, obviously, use response data).
The Google Drive SDK does not contain examples written in C ++, but as you can see in the reference section , all this is done with fairly ordinary HTTP GET, POST, etc.