hi… how to use software serial on arduino mega ( use pin 2 rx and 3 tx ). for harware serial is work perfectly but for software serial, its display failed disable echo on the serial monitor
This is not really a Blynk related question 
And also completely unnecessary as the Mega has 3 additional hardware serial ports on pins 14-19
If however you really want to use Software Serial, then I suggest reading up about it on the Arduino site.