SMTP Mail Error

My website is herehttps://3ik.org/yenibir3ikdoguyor/

/* Add your SMTP Codes after this Line */
$mail->isSMTP();
$mail->SMTPDebug = 0;
$mail->Host = 'smtp.gmail.com';
$mail->Port = 587;
$mail->SMTPSecure = 'tls';
$mail->SMTPAuth = true;
$mail->Username = "***@3ik.org";
$mail->Password = "*****";

// End of SMTP

i tried debug 1-2-0 in 1-2 status are doesnt even show error, changed port 587 to 465, nothing works.
searched old topics, no solution, talked with my server provider, smtp allowed, i used phpmailer before and still using.

on localhost error popup shows up, on server sending spinner keeps spinning.

please dont give me a "auto-response" about my problem.

thanks, have a nice day.

Thanks for response but i already used Documentation for forms and customized like in written document. Also my server has latest version of PHP. What should i do now?

Don't know why but, i set responder mail different from sender and it worked. Thanks.