Please don’t open old topics for your questions. I moved your post into a new topic.
Read through what examples there are for the Blynk Python library…
I recommend simply treating the LED Widget like any other widget and controlling it with a Virtual Write command.
This Blynk Python command will turn ON an LED Widget, set to V0.
The LED will take a range of 0 (OFF) up to 255 (Full ON) with the middle ranges being a variable “intensity”