You need to have a Yunohost server.
If you don’t have YunoHost, please see here to know how to install and enjoy it.
You can install it from the Yunohost Apps, select All apps in the dropdown menu, Search for Plume, click on install and follow the steps.
or
Using from an SSH connection to your Yunohost server:
sudo yunohost app install https://github.com/YunoHost-Apps/plume_ynh