curl --request POST \
  --url https://api.blsmsgw.com:8443/bin/send.xml \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --data 'USERNAME=<string>' \
  --data 'PASSWORD=<string>' \
  --data 'DESTADDR=<string>' \
  --data 'SOURCEADDR=<string>' \
  --data 'MESSAGE=<string>' \
  --data 'DLRADDRESS=<string>' \
  --data 'UDH=<string>' \
  --data 'UDHI=<string>' \
  --data 'VP=<string>' \
  --data 'SOURCEADDRTON=<string>' \
  --data 'SOURCEADDRNPI=<string>' \
  --data 'SOURCEPORT=<string>' \
  --data 'DESTPORT=<string>' \
  --data 'CONCATSMSREF=<string>' \
  --data 'CONCATSMSSEQ=<string>' \
  --data 'CONCATSMSMAX=<string>'

import requests

url = "https://api.blsmsgw.com:8443/bin/send.xml"

payload = {
    "USERNAME": "<string>",
    "PASSWORD": "<string>",
    "DESTADDR": "<string>",
    "SOURCEADDR": "<string>",
    "MESSAGE": "<string>",
    "DLRADDRESS": "<string>",
    "UDH": "<string>",
    "UDHI": "<string>",
    "VP": "<string>",
    "SOURCEADDRTON": "<string>",
    "SOURCEADDRNPI": "<string>",
    "SOURCEPORT": "<string>",
    "DESTPORT": "<string>",
    "CONCATSMSREF": "<string>",
    "CONCATSMSSEQ": "<string>",
    "CONCATSMSMAX": "<string>"
}
headers = {"Content-Type": "application/x-www-form-urlencoded"}

response = requests.post(url, data=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/x-www-form-urlencoded'},
  body: new URLSearchParams({
    USERNAME: '<string>',
    PASSWORD: '<string>',
    DESTADDR: '<string>',
    SOURCEADDR: '<string>',
    MESSAGE: '<string>',
    DLRADDRESS: '<string>',
    UDH: '<string>',
    UDHI: '<string>',
    VP: '<string>',
    SOURCEADDRTON: '<string>',
    SOURCEADDRNPI: '<string>',
    SOURCEPORT: '<string>',
    DESTPORT: '<string>',
    CONCATSMSREF: '<string>',
    CONCATSMSSEQ: '<string>',
    CONCATSMSMAX: '<string>'
  })
};

fetch('https://api.blsmsgw.com:8443/bin/send.xml', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_PORT => "8443",
  CURLOPT_URL => "https://api.blsmsgw.com:8443/bin/send.xml",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "USERNAME=%3Cstring%3E&PASSWORD=%3Cstring%3E&DESTADDR=%3Cstring%3E&SOURCEADDR=%3Cstring%3E&MESSAGE=%3Cstring%3E&DLRADDRESS=%3Cstring%3E&UDH=%3Cstring%3E&UDHI=%3Cstring%3E&VP=%3Cstring%3E&SOURCEADDRTON=%3Cstring%3E&SOURCEADDRNPI=%3Cstring%3E&SOURCEPORT=%3Cstring%3E&DESTPORT=%3Cstring%3E&CONCATSMSREF=%3Cstring%3E&CONCATSMSSEQ=%3Cstring%3E&CONCATSMSMAX=%3Cstring%3E",
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/x-www-form-urlencoded"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.blsmsgw.com:8443/bin/send.xml"

	payload := strings.NewReader("USERNAME=%3Cstring%3E&PASSWORD=%3Cstring%3E&DESTADDR=%3Cstring%3E&SOURCEADDR=%3Cstring%3E&MESSAGE=%3Cstring%3E&DLRADDRESS=%3Cstring%3E&UDH=%3Cstring%3E&UDHI=%3Cstring%3E&VP=%3Cstring%3E&SOURCEADDRTON=%3Cstring%3E&SOURCEADDRNPI=%3Cstring%3E&SOURCEPORT=%3Cstring%3E&DESTPORT=%3Cstring%3E&CONCATSMSREF=%3Cstring%3E&CONCATSMSSEQ=%3Cstring%3E&CONCATSMSMAX=%3Cstring%3E")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.blsmsgw.com:8443/bin/send.xml")
  .header("Content-Type", "application/x-www-form-urlencoded")
  .body("USERNAME=%3Cstring%3E&PASSWORD=%3Cstring%3E&DESTADDR=%3Cstring%3E&SOURCEADDR=%3Cstring%3E&MESSAGE=%3Cstring%3E&DLRADDRESS=%3Cstring%3E&UDH=%3Cstring%3E&UDHI=%3Cstring%3E&VP=%3Cstring%3E&SOURCEADDRTON=%3Cstring%3E&SOURCEADDRNPI=%3Cstring%3E&SOURCEPORT=%3Cstring%3E&DESTPORT=%3Cstring%3E&CONCATSMSREF=%3Cstring%3E&CONCATSMSSEQ=%3Cstring%3E&CONCATSMSMAX=%3Cstring%3E")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.blsmsgw.com:8443/bin/send.xml")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/x-www-form-urlencoded'
request.body = "USERNAME=%3Cstring%3E&PASSWORD=%3Cstring%3E&DESTADDR=%3Cstring%3E&SOURCEADDR=%3Cstring%3E&MESSAGE=%3Cstring%3E&DLRADDRESS=%3Cstring%3E&UDH=%3Cstring%3E&UDHI=%3Cstring%3E&VP=%3Cstring%3E&SOURCEADDRTON=%3Cstring%3E&SOURCEADDRNPI=%3Cstring%3E&SOURCEPORT=%3Cstring%3E&DESTPORT=%3Cstring%3E&CONCATSMSREF=%3Cstring%3E&CONCATSMSSEQ=%3Cstring%3E&CONCATSMSMAX=%3Cstring%3E"

response = http.request(request)
puts response.read_body

"<response><results><result><status>0</status><msgid>25593582</msgid><statustext>OK</statustext></result></results><balance>-818.6210</balance></response>"

{
  "error": "You do not have api permission"
}

{
  "error": "Authentication failed"
}