Hello,
Thank you for reaching out in the community. Please know the version of Twinmotion available with Revit Autodesk subscription, "Twinmotion for Revit", will not be accessed through the Epic Games launcher. Instead, it can be accessed through the Autodesk All products and Services page here.
Please see our FAQ and Youtube tutorial below for more information on installing and working with Twinmotion for Revit:
Best Regards,
Morgan