First of all, I see no mention in @Rom3oDelta7’s post from almost 3 years ago of using a NodeMCU as a Wi-Fi adapter for a Mega. An ESP8266 is mentioned, but I’m fairly certain that this would be the ESP-01 variation that’s commonly used for this.
Secondly, if I were asked to:
it would feel like I was back in school, not participating in a community forum. As a result, I’d probably tell you where to get off.
If you did a bit of searching then you’d come across this recent topic:
As you’ll see, if you take the time to read it, very few people thought that it was worth the time or effort to go down that route, but the author of the thread managed it working in the end.