Unfortunately there is no local interface so you will have to control it from the dashboard (and have a working internet connection)
You can add an ESP8266 to your dashboard just like an Arduino. Just select Arduino Uno for the device. There are lots of projects posted here, here’s one where I used a DHT11 sensor Battery Powered ESP8266 Temperature/Humidity Monitor with DHT11
It is possible to set a static IP address but I’m not sure on the process of getting it to work with Cayenne. I think you would have to choose the manual connection option. Maybe @kreggly has an answer there? Honestly would probably be easier to just set it in your DHCP server, that’s what I do.