Here are some photos showing where to set-up the modules inside the plane. It’s not recommended to use the antenna provided with the module, but if a good antenna is used on the transmitter it’s still possible to reach 5 km.
The wiring is extremely simple, 5 wires are needed between the APM and ULRS : GND, +5V, PPM, RX and TX.
In the example below, a hole is cutted below the plane for the battery. This frees up all the cockpit, and the canopy can be hermetically taped for example to cross the clouds.