I know almost nothing about the micro:bit, but all the examples and discussions here on the forum seem to use Bluetooth communication.
Blynk IoT doesn’t (yet) support Bluetooth, you you’d have to use the Legacy version of Blynk and I believe that new cloud account sign-ups for Legacy are now closed.
Also, I’m a bit bemused by the concept of using a micro:bit alongside a NodeMCU. I guess that you could use the micro:bit to control the GPIO pins of the NodeMCU and then have your Blynk code running on the NodeMCU, but I think I must be missing something in the bigger picture of what it is you’re trying to achieve.