Welcome to the Microsoft Q&A forum.
If I understand correctly you want to increase the limit for maximum number of rules per CDN endpoint which is currently 25 as documented here.
In order to increase this limit the process is to create a support request with us first and then the support engineer can file a formal request to the product team on your behalf to increase this limit. If you have a support plan please create the support request, if not please let me know I can help in this regard.
Thank you!
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