Connect the NeoPixel Data In Pin to D3 pin of NodeMCU, or else if you want to use your own pin, make appropriate changes to the pin number in in the _defines.h, and do connect the power line to a seprate output as the NodeMCU is not capable of driving such a high current consuming device.
Now open the sketch, and go to the _define.h tab and at the bottom of the page paste the token of the Blynk app.
Now upload the code, and go the the Blynk app, and add all the widgets as shown in the images, attach all the widgets to virtual pin accordingly. Now in the Menu widget, you need to add all the effect names manually. Add the names according to the instruction shown in the GitHub page.