I have a wordpress site deployed http://54.87.179.161/contact-us/ when i press submit buton on browser console it give me error

jquery.min.js?ver=3.7.1:2

    POST http://54.87.179.161/wp-admin/admin-ajax.php 404 (Not Found)`

I am using apache2 as a webserver to serve the site and using wpforms for this form and integrate mailgun with it https://wpforms.com/ this one

Thanks in advance

please help me how I can resolve this error.