ESP8266 Timed Button (Mimic a button press for a duration)

Firstly, you need to edit your post (using the pencil icon at the bottom of the post) and format the code correctly, so that it displays correctly:
Blynk%20-%20FTFC

Second,my using delay(3000); is very bad practice in Blynk. Whilst you might get away with it sometimes, you’ll almost certainly suffer disconnections if you use it regularly.
What you should do is to trigger a countdown timer of duration 3000 instead.

Take a look at this thread:

Pete.