Correct way to quit a Qt program?

Question

How should I quit a Qt Program, e.g when loading a data file, and discovered file corruption, and user need to quit this app or re-initiate data file?

Should I:

Answer 1

//How to Run App

bool ok = QProcess::startDetached("C:\\TTEC\\CozxyLogger\\CozxyLogger.exe");
qDebug() <<  "Run = " << ok;


//How to Kill App

system("taskkill /im CozxyLogger.exe /f");
qDebug() << "Close";

example