Looks to me like there are two plugs in that blue circle not connected to anything.
I recall reading after 21 they put a 4 pin trailer plug on bumper connector and the trailer camera connection was left unused under bed. Maybe it is that?
PRO POWER ONBOARD - 2KW INCLUDED ON THIS VEHICLE
EQUIPMENT GROUP 402A TREMOR SERIES
EXTENDED RANGE 36GAL FUEL TAN
ELECTRONIC AUTO TEMP CONTROL
REMOTE START SYSTEM
360-DEGREE CAMERA PACKAGE
LED SIDE-MIRROR SPOTLIGHTS
POWER-SLIDING REAR WINDOW
WIRELESS CHARGING PAD
OPTIONAL EQUIPMENT/OTHER
.18" ALLOY W/ DARK MATTE FINIS
.275/70R 18 ALL-TERRAIN
3.73 ELECTRONIC LOCK RR AXLE NO CHARGE
7000# GVWR PACKAGE
50 STATE EMISSIONS NO CHARGE
FORD CO-PILOT360 ACTIVE 2.0
.BLUECRUISE
.ACTIVE PARK ASSIST 2.0
TWIN PANEL MOONROOF
LINER-TRAY STYLE-W/CARPET MAT
PRO POWER ONBOARD - 2KW
INTERIOR WORK SURFACE
CNCTD BLT-IN NAV (3-YR INC)
AUTO START-STOP REMOVAL -
TRAILER TOW PACKAGE
.INTEGRATED TRAILER BRAKE CONT
B&O SOUND SYSTEM, 8 SPKR
PARTITIONED LOCKABLE STORAGE
4.10 FRONT AXLE W/TORSEN DIFF
BED UTILITY PACKAGE
I do have the trailer camera hookup using the 2 plugs in back of bumper and just got the tpms software to run on my tremor before it would reboot the computer every time, I selected it. But it looks like a power plug??? been wondering if i should find a cap and plug it?