Undefined reference to function in VlcQt (after installation)

Question

I recently installed VlcQt libary for ubuntu 16.04, but when I try to use it, all i get is undefined reference to 'some_function()'.

Currently I am trying to expose video player to QML.

Main.cpp

#include <QGuiApplication>
#include <VLCQtCore/Common.h>
#include <VLCQtQml/QmlVideoPlayer.h>

#include "Controller.h"

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    VlcCommon::setPluginPath(app.applicationDirPath() + "plugins");
    VlcQmlVideoPlayer::registerPlugin();

    Controller controller;
    QQuickWindow *quickWindow = qobject_cast<QQuickWindow *>(controller.view());
    quickWindow->show();

    return app.exec();
}

When I am trying to include libaries, Qt intellisense is detecting that this libary exists.

What am I doing wrong?

Thank you for your help!

//Edit:

I installed it via their repository:

add-apt-repository ppa:ntadej/tano 
apt-get install libvlc-qt-core2 libvlc-qt-widgets2 libvlc-qt-dbg libvlc-qt-dev 

//Edit: This is how I add libs in .pro file, already tried INCLUDEPATH too

LIBS += -lvlccore -lvlc