Hello @Thirumal Rao D !
In addition to KapilAnanth-MSFT suggestions , i would change the tone by adding that it is odd to try to access Application Insights via a WAF, at least in my eyes!
App Insights have their own API , hosted on Azure , protected by Azure as a Managed Resource and of course you can access it by Private Endpoint for enhanced security !
Also maybe this thread kinda helps but you are getting blocked by Anomaly Score so something is going on with the requests.
Kindly mark the answer as Accepted and Upvote in case it helped or post your feedback to help !