Right now there’s no thermocouple support in the app. You can still use a thermocouple to measure temperature, but you need to know the characteristics and do the conversion in your head.
So for example, a type K thermocouple plugged in to the Ω input on the “Aux voltage DC” setting would give you 41uV per degree C above the reference temperature. The reference temperature is the temperature of the meter, which you can read by setting one of the channels to the temperature setting. So if your meter temperature says 25C and your thermocouple voltage says 4.1mV, your thermocouple is at 125C (25C + 4.1mV/41uV).
Adding formula support within the app is on the to-do list, sorry it’s not there yet. Hope this helps.