2020+ 4Runners have this additional relay box that will need to be relocated in order to install the PowerTray.
Step 1: Slide the relay box out of its bracket by squeezing the two side tabs and unbolt the bracket from the vehicle.
Step 2: Remove the little locator tab by either cutting it off as I did, or you could simply bend it up and out of the way.
Step 3: Flatten out the bends on the vertical side of the bracket. (This step is technically optional. There is enough room to reinstall this relay box without bending the bracket. However taking out the bends makes the relay box sit lower and closer to the fender, which looks cleaner and doesn't crowd the wiring harnesses that come off of the braking assembly.)
Step 4: A little more wiggle room is needed for the relay box to install back in this cavity. So use a little straight out pressure and simply pop out this plastic clamp (Circled in red). It is no longer needed as all the wires in that main harness now have memory and the harnesses route has been established.
Step 5: Slide the relay box back into the bracket. With the bracket now straightened, it'll be necessary to remove the cover so you can get a wrench on the bolt to tighten it into the threaded M8 bolt hole closest to the firewall. Also, the harness coming out of the relay box may a little stiff due to the wires memory. So to bring back some of its flexibility, it helps to wiggle it around a little and massage it as you guide it along its new path. Hold the box vertical while you finish tightening the top of the bracket to the upper inner fender. It is perfectly fine to leave the bottom of the bracket floating as the top bolt provides more than enough force to secure this relay box.
Voilà! Now there's nothing preventing you from installing a PowerTray in your 2020+ 4Runner.