i want ask a question, blynk is mqtt broker or no?
no. Blynk uses own binary protocol
There is a basic MQTT broker built-in to the legacy servers, but it was never really implemented properly, and is of no use.
The easiest way is to use MQTT is with Node-Red and the Blynk ws or IoT contrib depending on whether you are using Blynk Legacy or the new Blynk IoT.
More info here…
I’ll be posting a Blynk IoT update to that topic soon.