Each of the pins in the trailer brake plug are individually fused, they're noted as "Trailer Tow"
Your '19 should be a Gen4 DS body truck, these fuse numbers should be the ones to check:
F53 ATR 20 amp Left Trailer lights
F81 ATR 20 amp Right Trailer lights
F29 FMM 20 amp Trailer Park lights
F28 FMM 20 amp Trailer Back up lights
F30 FMM 30 amp Direct from battery
F11 J Case 30 amp Brake Lever
Use a fuse checker or multi meter to verify if the fuses are good. The fuses are not energized unless that circuit/lights are On.
Another thing to check would be to pull the plug out of the back of the 7 pin plug and check for power there.