Nest needs C wire - Goodman PGB024075-1
You'll need to do a bit of wiring work
Unfortunately, your unit doesn't expose the C terminal in a convenient place, so you'll have to do a bit of wiring to add it.  You'll need a ¼&quot; &quot;piggyback&quot; tab terminal suitable for 18AWG wire like the Panduit one depicted below, a 3' length of 18AWG blue TFFN wire, and a wirenut suitable for 2 18AWG wires for this.

Crimp the tab terminal onto the 18AWG TFFN, then stuff it down through the grommet in the bottom of the wiring compartment alongside the other thermostat wires. Once that's in place, slide one of the tab terminals off of the C terminal (the one with the three white-ish wires on it) of the 24V transformer in your unit and slide the &quot;piggyback&quot; terminal on where the terminal you removed went, then slide the terminal you removed onto the tab provided by the &quot;piggyback&quot; terminal.  You can then wirenut the other end of that new blue wire to the wire in your thermostat cable you wish to use as a C wire.