This shield is designed for the ESP-01S WiFi module and HC-06 Bluetooth module. Onboard comes with interfaces for module.
The shield also comes with 2 buttons for connecting WiFi modules. To be specific, RST button is connecting to the WiFi module’s reset interface. KEY IO0 button is for the WiFi module’s IO0 interface.
It is very easy to connect the shield to EASY Plug control board for communication using only an RJ11 cable.