Install Latest Firmware on your NodeMCU or ESP8266

1. ChiliPeppr has several pre-compiled firmware versions available on the Github repository for this workspace. https://github.com/chilipeppr/workspace-nodemcu/releases
2. You can also build your own at NodeMCU-build.com but this service can sometimes be down. You may also consider following their instructions for setting up Docker and building on your own local box.
3. You can flash the firmware by using nodemcu-flasher on Windows or Python Esptool on Linux. You can also try the flasher tools from Espressif Flash Download Tools page.