Please install the latest version (3.34 LTR or 3.40) of QGIS for your platform. Prior versions will not necessarily work properly with our plugins or mapping projects.
The Mappy plugin is available at plugins.qgis.org/plugins/mappy
The OpenCraterTools is available at plugins.qgis.org/plugins/opencratertool
At this link you will find relevant documentation for Mappy.
Please install VRGS, you will receive a license key when you register.