HTTP json post on SİM800L problem. HTTPACTION responses are 301, 603 and 606

#include \<SoftwareSerial.h\>
String apn = "internet";               //APN
String apn_u = "";                     //APN-Username
String apn_p = "";                     //APN-Password
String url = "https://airpm.io/denek/GetData";  //URL of Server - Website is https://
SoftwareSerial mySerial(14, 12); // sim800l_TX_pin, sim800l_RX_pin
int counter = 0;
void setup()
{
Serial.begin(9600);
Serial.println("SIM800 AT CMD Test");
mySerial.begin(9600);
delay(5000);
while (mySerial.available()) {
Serial.write(mySerial.read());
}
delay(2000);
configure_gprs();
}
void loop() {
counter++;
String data = String(counter); //write your data here
send_to_server("{"KEY":" + data + "}");
delay(2000);
}
void send_to_server( String data) {
String sendURL = url;
Serial.println(" --- Start GPRS & HTTP --- ");
send_to_serial("AT+SAPBR=1,1");
send_to_serial("AT+SAPBR=2,1");
send_to_serial("AT+HTTPINIT");
send_to_serial("AT+HTTPPARA=CID,1");
send_to_serial("AT+HTTPPARA=URL," + sendURL);
send_to_serial("AT+HTTPPARA=CONTENT,application/json");
send_to_serial("AT+HTTPDATA=" + String(data.length()) + ",10000");
send_to_serial(data);
//send_to_serial("AT+HTTPSSL=1");
send_to_serial("AT+HTTPACTION=1");
send_to_serial("AT+HTTPREAD");
send_to_serial("AT+HTTPTERM");
send_to_serial("AT+SAPBR=0,1");
}
//AT+CGACT=1,1
// "AT+CGDCONT=1,"IP","\<APN\>","0.0.0.0",0,0"
// "AT+CGDNSIP=1,"\<PRIMARY_DNS\>","\<SECONDARY_DNS\>""
//  send_to_serial("AT+HTTPSSL=1");
void configure_gprs() {
Serial.println(" --- CONFIG GPRS --- ");
send_to_serial("AT+SAPBR=3,1,Contype,GPRS");
send_to_serial("AT+SAPBR=3,1,APN," + apn);
if (apn_u != "") {
send_to_serial("AT+SAPBR=3,1,USER," + apn_u);
}
if (apn_p != "") {
send_to_serial("AT+SAPBR=3,1,PWD," + apn_p);
}
}
void send_to_serial(String command) {
Serial.println("Send -\>: " + command);
mySerial.println(command);
long wtimer = millis();
while (wtimer + 5000 \> millis()) {
while (mySerial.available()) {
Serial.write(mySerial.read());
}
}
Serial.println();
}

I tried to post json data to a website on simcard(SIM800L).
The website is https://
When I put this line send_to_serial("AT+HTTPSSL=1"); out of comment, I get 606 error. When its in comment, I get 603 error.
When send_to_serial("AT+HTTPSSL=1"); line is in comment and When I use http:// url I get 301 error.

I use ESP32-Wroom-32D, not an arduino(ATMEL)

I found the problem,
The SIM800L has TLS1.0 but our website has TLS1.2.
So, I lowered the website's TLS level. It worked.