The ESP32 has Wi-Fi modules with full TCP/IP stack and microcontroller capability. For the product, DroneBridge offers a transparent and bidirectional series to the WiFi bridge. Typical WiFi range is ~50m-200m depending on antennas. High gain directional antennas (5db) will offer greater range. Use WIFI V3.0 32-bit CPU. It runs faster and supports TCP/upp. Convenient interface for parameter setting. Since WiFi V3.0 uses mavlink v2.0 protocol, it only supports pixhawk flight control, not APM flight control. 

The wiring is very simple and similar for all devices when connecting to the Pixhawk TELEM1/2 ports. You can use 2.54mm pitch header connectors or solder PX4 telemetry cables directly to the board.