This project uses some QML Modules which are not available in Qt6.2.2

[shujaatak]

QQmlApplicationEngine failed to load component
qrc:/ExampleMiscellaneousGauges.qml:27:9: Type TankGauge unavailable
qrc:/Misc/TankGauge/TankGauge.qml:22:9: Type LeftTankGauge unavailable
qrc:/Misc/TankGauge/LeftTankGauge.qml:3:1: Type BaseTankGauge unavailable
qrc:/Misc/TankGauge/BaseTankGauge.qml:6:1: module "QtQuick.Controls.Styles" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:5:1: module "QtQuick.Extras" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:4:1: module "QtGraphicalEffects" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:6:1: module "QtQuick.Controls.Styles" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:5:1: module "QtQuick.Extras" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:4:1: module "QtGraphicalEffects" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:6:1: module "QtQuick.Controls.Styles" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:5:1: module "QtQuick.Extras" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:4:1: module "QtGraphicalEffects" is not installed

[CanDursun]

QQmlApplicationEngine failed to load component
qrc:/ExampleMiscellaneousGauges.qml:27:9: Type TankGauge unavailable
qrc:/Misc/TankGauge/TankGauge.qml:22:9: Type LeftTankGauge unavailable
qrc:/Misc/TankGauge/LeftTankGauge.qml:3:1: Type BaseTankGauge unavailable
qrc:/Misc/TankGauge/BaseTankGauge.qml:6:1: module "QtQuick.Controls.Styles" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:5:1: module "QtQuick.Extras" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:4:1: module "QtGraphicalEffects" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:6:1: module "QtQuick.Controls.Styles" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:5:1: module "QtQuick.Extras" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:4:1: module "QtGraphicalEffects" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:6:1: module "QtQuick.Controls.Styles" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:5:1: module "QtQuick.Extras" is not installed
qrc:/Misc/TankGauge/BaseTankGauge.qml:4:1: module "QtGraphicalEffects" is not installed

Yes, this is not about the repo. You need to compile this project in Qt 5.15 in order to make it work.