@MaBe Thank you for your response sir. please see my edit above in OP post.
I removed DFU_UPDATE_BUILD=1 and added RELEASE=1 as you suggested, and still the device is not showing up as TTY to send javascript to. The WebIDE also doesn't recognize the device after flashing.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@MaBe Thank you for your response sir. please see my edit above in OP post.
I removed DFU_UPDATE_BUILD=1 and added RELEASE=1 as you suggested, and still the device is not showing up as TTY to send javascript to. The WebIDE also doesn't recognize the device after flashing.