Avrdude error when uploading

[EJ Salga]

I get this error:

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00

When I upload this code to my Nano:

#include <Servo.h>

Servo myservo;  int potpin = A0;int val;
void setup() {
  myservo.attach(9);
}
void loop() {
  val = analogRead(potpin);
  val = map(val, 0, 1023, 0, 180);
  myservo.write(val);                  delay(15);
}

The Arduino help center says I might have selected the wrong board and
port. So I reselected the Nano board and put in COM3. I also reinstalled
the CH340 driver as my Arduino is a clone. I’ve tried reuploading and
restarting but nothing seems to work and I get the same error.

Any help is much appreciated.