You need to
Install the server, for example on a Raspberry Pi. (See documentation).
Configure your measurement hardware. Out of the box, Festival Grid supports all devices that Tasmota supports. (See Devices).
Make your hardware known to Festival Grid by scanning/provisioning it (in the web backend, go to
Nodes & Devicesand click
Scan for Devices, select the devices you want to use and click
In the web backend, place
Connectionson the map.
If you want to use the companion app, install it on your phone. (See smartphone app).