htaccess referer

I am trying to use the .htaccess to secure my WordPress login. There are plenty of these out there and the most effective includes the addition of the following to htaccess:

RewriteEngine on
RewriteCond %{REQUEST_METHOD} POST
RewriteCond %{HTTP_REFERER} !^http://(.*)?example\.com [NC]
RewriteCond %{REQUEST_URI} ^(.*)?wp-login\.php(.*)$ [OR]
RewriteCond %{REQUEST_URI} ^(.*)?wp-admin$
RewriteRule ^(.*)$ – [F]

Code (markup):

Here is my setback, i dont want the referrer to be the site, i want it to be my web server/plesk. There is a login link from each subscription that does some redirect magic and logs you in. I was hoping to make my server the referrer but cannot execute it. Any recommendations?

 

Does your web server/plesk have a url you could use? Have you tried changing (.*)?example\.com to (.*)?yourpleskdomain\.com? You could also use an ip 123\.456\.789\.323 I believe

 

I have tried that, also tried https, i simply can't get anything to work. when i click login from plesk the url looks like this,

https://my.pleskdomain.com:8443/modules/wp-toolkit/index.php/domain/redirect/id/25

Code (markup):

then redirects straight to wp-admin so its posting to the login somehow, i should be able to make this the referer somehow.