Adding widevine to my QT project doesn't work

I downloaded the widevinecdm.dll file from Chrome, then in my .pro file in QT i enabled propietary codecs as said here i added also the path to the dll like this QTWEBENGINE_CHROMIUM_FLAGS=--widevine-path="C:\Users\FRANC\OneDrive\Desktop\Programacion\Proyectos\C++\widevinecdm.dll" but i still can't play netflix or any streaming service. any ideas?