On the Smappee Genius you can set a fixed IP via the networking page in the expert portal.
Smappee Connect and EV Line products
There is no option to set a fixed IP on the device itself.
Please contact the IT managing the network on which the devices are being installed to assign a fixed IP via the DHCP server. You will need to provide them the MAC adresses of the products for this. To know the MAC addresses please contact Smappee Support and provide the serialnumbers of the products.