Hotkey is invalid on ubuntu18.04

[swkee]

QHotkey version:1.5.0 on ubuntu 18.04, qt5.15.8
1,Compiling project, unable to display app。 then modify code <qhotkey_x11.cpp> as below:
......
Display *display = QX11Info::display();
if(display ){
display = XOpenDisplay(NULL);
}
after that, i can run the app, but shortcut didn't work.