I have followed the instructions in the following QGIS help doc under the section: 'Using PyQGIS in Custom Applications'Īfter attempting to run the script I realized a dll plugin was missing. I am using a Python 3.7 installation separate from what comes with OSGeo4W and attempting to integrate qgis functionality. I currently am sticking with the OSGeo4W web installer installation. I've attempted using various installs of qgis 3.x+ including the standalone installer and OSGeo4W web installer. I am implementing qgis 3.4.3 in a custom application, but when I instantiate the QgsApplication() class, I receive the error 'Could not find the Qt platform plugin 'Windows' in ''.