As I stated before, we are not here to write your code for you… you will need to learn how to code for Blynk on your own, but we will help with specific issues as you learn.
For example, controlling a servo motor from a slider is very easy…
BLYNK_WRITE(Vx) // Slider set to Vx and to range 0-180
{
int SrvoPos = param.asInt(); // get slider value
Servo1.write(SrvoPos); // move servo to value
}
But not sure what you mean by automatic mode… you want the servo to just keep moving back and forth or based on some other form of sensor input?