The file is under Release directory which is the binary file output place.
The other files would be presented once it was edited. But the text file under release directory doesn't.
I tried to use git bash.
git add /d/test/ClipBird/Release/bal.txt
fatal: D:/test/ClipBird/Release/bal.txt: 'D:/test/ClipBird/Release/bal.txt' is outside repository