This step is not yet a legal requirement for making your home available during the day, unlike starting a seasonal rental activity in Paris and in high-demand areas (28 municipalities in France).
Indeed, the activity enabled by We Are Scene falls outside this requirement, which was not designed for this relatively new type of use. That said, we advise our hosts to do it as a precaution.
Go to your local town hall's (Mairie) website to begin this process.