robots.txt is in the public_hmtl of the web site. This is the base directory. It is lower case
User-agent: *
Disallow: /wp-admin/
Disallow: /wp-includes/
Disallow: /cgi-bin/
Disallow: /wp-admin/
Disallow: /wp-includes/
Disallow: /xmlrpc.php
Disallow: /wp-content/plugins/
Disallow: /wp-content/cache/
Disallow: /wp-content/themes/
Disallow: /trackback/
Disallow: /feed/
Disallow: /comments/
Disallow: /tag/
Disallow: /category/
Disallow: /trackback/
Disallow: /feed/
Disallow: /comments/
Disallow: /*?
Disallow: /index.php # separate directive for the main script file of WP
Disallow: /*.php$
Disallow: /*.js$
Disallow: /*.inc$
Disallow: /*.css$
User-agent: Googlebot-Image
User-agent: Google
User-agent: Bingbot
`