In order to run the QT application on the toradex module, the linux operating system should include QT packages to do that we are suggesting to do Build and Deploy the image.
In order to build QT application for the device on the development machine, cross compile SDK needed for that we are suggesting to do Build and Install the SDK on the development machine.
After installing the SDK, QT environment needs to configure to build and deploy the QT application for the device. Please follow this procedure to do that.
There are 3 options to get QT enabled image, you would choose convenient one for you as described in the documentation. Please let us know if you have any specific question.