How to set up and send mail for recovering account password using phpmailer in Centos 7

Hello everyone, currently my website is in need of a password recovery system by email. I’ve got the recovery site, and it’s written in php using phpmailer on xampp. It worked fine, but when I put it on VPS centos 7, it didn’t work anymore, here is my config to listen to the gmail server:

include "../vendor/autoload.php";

            $mail = new PHPMailer;
            $mail->isSMTP(true);
            $mail->Host = "smtp.gmail.com";
            $mail->SMTPAuth = true;
            $mail->Username = "my_email_username";
            $mail->Password = "my_email_password";
            $mail->Port = 587;
            $mail->IsHTML(true);
            $mail->CharSet = 'UTF-8';
            $mail->From = "my_email";
            $mail->FromName = "No Reply";
            $mail->Subject = $subject;
            $mail->Body = $body;
            $mail->AddAddress($email_to);

if (!$mail->send()) {
                echo 'send_mail_failed';
            } else {
                $update_password_byEmail = "UPDATE account SET password=:gen_password WHERE name=:currentUser AND email=:currentEmail;";
                $stmt_gen_pass_update = $sqlWeb->prepare($update_password_byEmail);
                $stmt_gen_pass_update->bindValue(':gen_password', md5($password_generate));
                $stmt_gen_pass_update->bindValue(':currentUser', $usernameOfEmail);
                $stmt_gen_pass_update->bindValue(':currentEmail', $target_email);
                $stmt_gen_pass_update->execute();
                $stmt_gen_pass_update->closeCursor();

                echo 'send_mail_successful';
            }
        } else {
            echo 'send_mail_error';
        }

Anyone who has experience in installing and operating it please help me find a solution to install and use phpmailer on centos 7. I am new in this field, and am trying to improve my experience. myself. Thank you very much.