htaccess block and allow sites from the same domain name - .htaccess

Question

I run a service where I offer css files and scripts and images for a third party website www.myfantasyleague.com that is a football hosting service for fantasy football and recently they have went through some changes over the last couple of years.
I am trying to block certain websites on their servers that are using my work fraudulently, while allowing the folks whom purchase my work on the same domain to be able to use my work and it not be blocked by the HTA file. Once you create a football site MFL gives it a permanent server number and 5-digit code that never changes now from each year it stays the same. Here is a link to a MFL search for the word football, and you can see there are many sites and if you click on a few they all have different 5 digit IDs and some have different server ID’s.
The site I want to start with to block, would be this site url below, and the MFL domain has an option to have http and https now, so getting both protocols would be idea.
SITE TO BLOCK EXAMPLE
https://www67.myfantasyleague.com/2019/home/63928#0
SITE TO ALLOW EXAMPLE
http://www51.myfantasyleague.com/2019/home/46087#0
On myfantasyleague domains they give each site its own 5-digit unique code at the end of the url, and also many are on different server id’s, like the www67 and the www51, and you see those 2 links one is https and one is http.
In the past I use to use this code below and it will still work today, however once I add it to my root access file, it takes out both sites and I can’t have that, as I want to be able to control which sites are blocked by the server number and the 5-digit league ID if possible.
CODE THAT I TRIED THAT WORKED BUT KILLS ALL SITES FROM THAT DOMAIN NAME.
RewriteEngine On
RewriteCond %{HTTP_REFERER} https?://(www\.)?www(67).myfantasyleague.com.+(63928) [NC,OR]
RewriteRule .*\.(jpe?g|gif|bmp|png|js|css)$ [L]
Maybe i can turn that URL to be blocked into the actual IP and try blocking the IP?
I don't know what else to try and it might not even be possible i dont know. I appreciate any and all feedback.
Thank you

Answer 1

Though the pattern you posted certainly can be improved there is no reason why it should "block" all referrers from that host, if those sites send a referrer header at all ... Keep in mind that such header is optional and can be modified easily, so anyone can work around limitations you implement based on that header.
Blocking an IP on the other hand means you block all services from that host which is not what you want, as I understand. The numerical addition to the "www" prefix indicates that the service operator uses sharding to balance request load, an old and outdated approach. You can expect that to change any time, either for individual sites or in general, so better not rely on it. You are only interested in the numerical ID at the end of the referring URL.
Your issue with that approach you posted however is the actual rewriting rule: it is syntactically invalid. So I would expect it to raise an internal error, thus blocking all requests. I would suggest something like this instead:
RewriteEngine On
RewriteCond %{HTTP_REFERER} !/63928$ [OR]
RewriteCond %{HTTP_REFERER} !/63927$ [OR]
RewriteCond %{HTTP_REFERER} !/63926$
RewriteRule ^ [F,NC]
This would actively white list specific sites by mentioning their numerical ID and block all other requests by sending out a "Forbidden" header.
Please note that I have not actually tested above code, it might contain some minor glitch which you might have to fix. For such things it is important to have access to the http servers error log file. Not sure if you have it in your situation...