The fuse may be labelled 'Radio', but it probably powers other circuits as well.
Part of the confusion is that there are 2 fuse boxes. The underhood fuse/relay box is called the Power Distribution Center or PDC.
The side dash fusebox is called a Junction or Fuse Block.
If the circuit is discharging the battery, we want to find a battery-powered or (B+) fuse. This can also be called an IOD (ignition-off draw) fuse. There is always a few mA of current draw to keep clocks & memories/adaptives supported.
Something is staying on.
Fuse #18 in the PDC supplies IOD to the radio on a Pk/LBu wire. It then goes to Fuse #13 in the Fuse Block and exits as a Pk wire to S(plice)220.
The Siren is the export security system and doesn't apply to the NAFTA market.
The Pk wire goes all over the place & powers things that could discharge the battery. Is the rear cargo lamp or a visor vanity lamp staying on? Is the instrument cluster going to sleep after shutdown?
A quick way to find this 'short' is to install a current draw indicator. A smaller bulb )like a sidemarker lamp, will glow brighter with less current draw:
Then the next fun part is to begin unplugging things until the light goes out. Keep narrowing down the draw opportunities as you get closer to the culprit.
0.57 A=570 mA. Too much. Are you able to lock & unlock the doors? Does playing with the power lock switches change draw?
It may very well be related to the power locks. If an internal 'short' in that module is drawing current, that could be the issue.
A component that draws 500 mA may be warm to the touch. Try unplugging the RKE module.
Your main public library may have useful manuals with wiring diagrams (usually not in Chilton's or Haynes).
They may also have a subscription to Alldata that you can print copies from.
The factory service manual (ebay?) is the best and will likely pay for itself.