how do I prevent google to crawl contact.php page?
 

my site is in html and I have created php for request and response form submission to the server. I have got an 404 error for that page how do I prevent google to crawl it
Can I write page level below code:

If yes than How do I use that in code

Through Robot.txt you can prevent search engine crawler to visit your website. You can add this code in your website.