If your site shows a 404 error after installing WordPress, you can follow these steps to resolve it.
First, click on "Manage" for the website, as shown in the image.
A new page will open, and you’ll need to scroll down a bit. Then, click on the "Rewrite Rules" option.
Next, clear everything in the empty box and paste the provided code.
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
After that, click on "Save Rewrite Rules" to complete the process.