gozap_api/User/login.php

<?php
include_once "../include/DB.php";
$userPhoneNumber="";
$userPassword="";

if (isset($_POST["phonenumber"]) && !empty($_POST["phonenumber"])) {
   $userPhoneNumber=$_POST["phonenumber"];
}

if (isset($_POST["password"]) && !empty($_POST["password"])) {
   $userPassword=$_POST["password"];
}

$sql = "SELECT UserID,
UserName,
PhoneNumber,
IsAdmin,
CreatedAt AS UserCreatedAt,
UpdatedAt AS UserUpdatedAt
FROM user WHERE PhoneNumber='$userPhoneNumber' AND Password='$userPassword'";
$result = $conn->query($sql);

if ($result!== false && $result->num_rows > 0) {
  $listArray = [];
  // output data of each row
  while($row = $result->fetch_assoc()) {
    // Declare an array 
    $value = array(
        "UserID"=>(int)$row["UserID"],
        "UserName"=>$row["UserName"],
        "PhoneNumber"=>$row["PhoneNumber"],
        "IsAdmin"=>(int)$row["IsAdmin"],
        "UserCreatedAt"=>$row["UserCreatedAt"],
        "UserUpdatedAt"=>$row["UserUpdatedAt"],
        "Message"=>"Your login successful"
    );
    
    $listArray[]= $value;
  }

  $count = count($listArray);

  if($count==1){
    // Use json_encode() function
    $json = json_encode($listArray[0]);
  }else {
    // Use json_encode() function
    $json = json_encode($listArray);
  }
  // Display the output
  echo($json);
} else {   
  http_response_code(404);
  $errorMesage= $conn->error;
  if ($errorMesage=="") {
    $errorMesage = "User name or password incorrect";
  }
  // Declare an array with error message 
  $value = array(
    "Message"=>"Your login failed",
    "Error"=>$errorMesage
  );
  // Use json_encode() function
  $json = json_encode($value);
  // Display the output
  echo($json);
}
$conn->close();