Why the Folder did not Added to the Setup Files and how to add it

Question

i created Video and Audio Player playing files from folder it has song and video, and  i added this Folder to My Project project .

so in this way i tell the compiler first to take the path of the Folder that i added it inside my Project :

// "SongVideoFolder" Name of the Folder  inside my project //

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string SongVideoFolderPath = Environment.CurrentDirectory;

SongVideoFolderPath +="SongVideoFolder";

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so in this way the compiter knews the path of folder that contain the audio and Video to play them

and everything going  well , and when i run the program and play music or vedio it is working well just when i did Setup file to do Setup for the program ,,,and after i run the setup then tried to run the program >>>>> the program give error that can not find SongVideoFolder  folder ..... and i open the folder where i told the Setup File to extract file to .... i Did not find the Folder SongVideoFolder  So my questions are :

1- Why the Folder did not Add to the Setup Files

2-  and how to add the Folder to Setup Files