How to change the default board name (network name) of ESP8266 nodemcu?

with the classic Blynk setup: >>Blynk.begin(auth, ssid, pass)<<
my DSL router displays my board as (e.g.) ESP-0826FA (board, OS, Server name).
What do I need to do to change it ?
Thanks, Markus

Try this BEFORE the Blynk.begin in your code: