Prerequisites
If not already done so already, install Arduino software and make basic connections, as described in page for MRMS ESP32: Arduino, IMU, eFuse, BT, WiFi, CAN Bus (mrm-esp32).
Examples
WiFi is a feature of ESP32 chip and it is not related to the rest of the ML-R system. Therefore, any ESP32 WiFi example will work. Different examples can be found here.