C++ Import File into Visual Studio 2017 So Program Can Open It

Can someone tell me how to add a file in Visual Studio 2017. I have a Invent.in file which a list of grocery items and I cannot get the file to open. I feel that I have not incorporated it into the project within Visual Studio properly and cannot figure out what I am doing wrong. I have seen guidance saying I simply add the file to the project as well as saying I have to add the file path somewhere.

Below is the code I have to open the file though I do not think that is my issue.

// Open Invent text file ifstream inventoryFile; inventoryFile.open("Invent.in");