how to use a .lib fule in c++ Qt creator without header

i have this lib file : [mylibfile.lib][1]

The tree of library is :

|--3rdparty/LinphoneSdk/include
     ||------------------------nothing 
|--3rdparty/LinphoneSdk/lib
     |---------------------linphone++.lib

But I do not know how to use linphone++.lib file.

If anyone can help me I will be very grateful.

i use Qt Creator 4.8.0 (Enterprise)

Is it possible to use .lib file without header files ?

i use this :

#include "mainwindow.h"
#include <QApplication>
#include <linphone++/linphone.hh>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

But this throws an error :

linphone++/linphone.hh file not found

in my untitled2.pro , i have this codes :

#-------------------------------------------------
#
# Project created by QtCreator 2019-01-15T00:01:40
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = untitled2
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

CONFIG += c++11

SOURCES += \
        main.cpp \
        mainwindow.cpp

HEADERS += \
        mainwindow.h

FORMS += \
        mainwindow.ui

INCLUDEPATH += 3rdparty/LinphoneSdk/include

LIBS += -L"3rdparty/LinphoneSdk/lib" -lLinphoneSdk

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target