I use Blynk to controll my external lights that have no other switch. Since in the winter I work with the gloves, I found it quite annoying to take them off, open the app and press the button. I already use nfc tags for some other home automation tasks and my idea is just to put (unlocked) phone to nfc tag and the lights will turn on.
But I have no idea how to execute it…
Since Blynk doesn’t have any NFC widgets, you will need to do it with 3rd party apps and possibly webhook links to the Blynk server (assuming you are using the Cloud Server, but it doesn’t really matter)
I already tried to create Tasker action with the same data for webhooks that I use for IFTTT and then use it for NFC trigger, but gives me just this error
Error parsing body param
This is not the tasker forum 
you will get better traction there first… then we can help with the Blynk side.
Besides… can’t see anything on your screenshot to show the precise webhook data you are trying to send.
