You need the Arduino IDE.
Instructions here : https://github.com/esp8266/Arduino
- https://github.com/adafruit/Adafruit_NeoPixel
- https://github.com/bblanchon/ArduinoJson
Open the laumio.ino sketch.
Select the board in the board type to "WeMos D1 R2 & mini".
You can now compile and flash the sketch to the board.