HC 12 with Servo

Well I found the optimal mapping values but the servo is still shaking. Here is the code :
Transmitter :

#include <SoftwareSerial.h>

int ROT ;
SoftwareSerial HC12(10, 11); 
void setup() {
  Serial.begin(9600);             
  HC12.begin(9600);               
  
}
void loop() {

int ROT = analogRead(A0);
ROT = map(ROT , 515 , 1023 , 1585  , 1800) ;
Serial.println(ROT);
HC12.write(ROT);
delay(100);


  }

Reciever :

#include <Servo.h>
#include <SoftwareSerial.h>

int ROT ;

Servo myServo;
SoftwareSerial HC12(10,11); 
void setup() {
  myServo.attach(6);
  HC12.begin(9600); 
  Serial.begin(9600);

  
}
void loop() {
          
   while ( HC12.available()>0) {       
   
   ROT = HC12.read();
   Serial.println(ROT);
   
 
    myServo.write(ROT);
  delay(100);

 
   }
   }

Any ideas?