Page 5 tells you what to do... You connected a temp probe (thermistor) to Connection A and connect the heater's fireman's switch to Connection B..
Basically, all the IntelliConnect does is close a small internal relay.. This is connected in series with the heater's firemans circuit.. When the relay inside the IntelliConnect is open the heater will not run.. When the relays is closed, the heater will heat. The IntelliConnect looks at the temp sensor plugged in port A and compares it with the set point you have set in the IntelliConnect app.. If the water is colder than the set point, the relay will close, and the tell the heater to turn on. Once the water gets up to the set point, the relay will open and the heater will shut off.