Drive a 20A load (12V) with an MCU at 3.3V
The choice of switch depends on your preference for size of heatsink and far more choices if you choose low Vt (threshold) logic-level SMT. and use twisted pairs for lower RF impedance and lower EMI.
If using a higher Ron , such as your choice of FET you would need a small CPU heatsink and 2W fan to cool 20W of switch losses of 1V on a proposed 12Vx20A =240W load that would only get 11V at this current and less on startup.
Consider the Switch Power loss vs contact resistance

R [mΩ] . . . .        Pd [W] @ 20A  . . . Type . . . . . Heat
78 . . . . . . . . 31 . . . . . . . . . . . . IRL540 . . .   fail
8 . . . . . . . . . . 3.2 . . . . . . . . . . many SMT . . .  needs &gt;=5W heatsink 1 THT part $18
400µOhm . . . 160 mW . . . . . . SIR178DP-T1-RE3   $2.46 . . . needs SMT DIY soldering
/w Cu area.

Last option probably would need heavy traces or wire to large terminal block for welding wire to minimize cable resistance to same as switch on a small copper breadboard.
Be sure to include reverse diode from Drain to 12V because all wire has inductance and if your fridge has a pump, much more energy stored will kick back.