How to remove CyberPanel installed index page from wordpress

A few days ago I installed wordpress on 3 domains but after 2,3 days on my 1 site it was showing Cyberpanel installed page. Then I removed that index.html file from file manager now my site home showing 404 not found

When you create a website the cyberpanel index.html is auto-added from /usr/local/CyberCP/index.html ( if you need you can customize it) ,

but yes when you delete the index.html from site document root ( public_html) it will show 404 since there is no default index page in the site.
make sure your site have proper Wordpress installation , if it didn’t have index pages it will show 404 which is normal.