Getting the error The project cannot use itself

[sanchit.kktrading@gmail.com]

Hi,
I was trying to use a reference of a project into my main project but while specifying the project usages , "The project cannot use itself "error is coming, could someone explain what needs to be done and why this error is coming. The screenshot of the error has also been attached below.

Thanks and regards,
Sanchit Jain.