Wi-Fi Thermostat connection for TWE040E13FA1 Trane Electric Air Handler and Heat Pump

Wi-Fi Thermostat connection for TWE040E13FA1 Trane Electric Air Handler and Heat Pump

I want to set up a wifi thermostat (TH6320WF2003-U) that needs a C wire for its 24v power supply to my Air handler. I cannot find the C terminal on the Air handler unit so not sure which wire to use, Anyone with a way to wire these two units? Thanks!