Digital Ocean Managed MySql DB can not connet via PHP project hosted on Bigirock Server [duplicate]

I have domain and hosing in bigrock linux shared server.
Digital Ocean Managed MySql DB successfully connect via Navicat for Mysql but when i use these credentials in my php project its not working showing error

Basically i am trying to connect Digital Ocean MySQL DB with php project which is hosted on Bigrock shared linux server.

Code i Have Used

<?php
ini_set('display_errors', 1); 
$servername = "db-mysql-db.ondigitalocean.com"; // CHANGED FOR SEQURITY
$username = "repo_Jyoti"; // CHANGED FOR SEQURITY
$password = "AVNbJQM";  // CHANGED FOR SEQURITY
$dbname = "repo_Jyoti"; // CHANGED FOR SEQURITY
$port = "27850"; // CHANGED FOR SEQURITY
    $options = array(
                  PDO::ATTR_PERSISTENT    => true,
                  PDO::ATTR_ERRMODE       => PDO::ERRMODE_EXCEPTION
              );
   
    $dsn = 'mysql:host=' . $servername . ';port=' . $port. ';dbname=' . $dbname;    // Create a new PDO instanace
    try{
        $dbh = new PDO($dsn, $username, $password, $options);
       
         echo "Connected successfully";
    }
    // Catch any errors
    catch(PDOException $e){
        echo "Connection failed: " . $e->getMessage();
    }    
?>

ERROR : Connection failed: SQLSTATE[HY000] [2002] Connection refused

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if you want to see the errors by yourself please visit
https://wapi.rentdekhoo.com/bbsapi/repo_Offline/testconn.php