...This is done by users request, to limit amount of external dependencies in different production setup environments. All methods end extras described below are compatible between each other and can be used together. We still maintain special case for Flask = 1.1.4 support (the latest version in 1.x.x branch). To install flask-mongoengine with required dependencies use legacy extra option. Flask-mongoengine can be installed with Flask-WTF and WTFForms support. This will extend project dependencies with Flask-WTF, WTFForms and related packages.