Update reporting docs (#87651) (#87920)

docs/user/reporting/response-codes.asciidoc

@@ -9,7 +9,7 @@ the POST URL. This is true even if the job somehow fails later, since report
 generation happens asynchronously from queuing.
 
 - **`400` (Bad Request)**: When sending requests to the POST URL, if you don't use
-  `POST` as the HTTP method, or if your request is missing the `kbn-version` header,
+  `POST` as the HTTP method, or if your request is missing the `kbn-xsrf` header,
   Kibana will return a code `400` status response for the request.
 
 - **`503` (Service Unavailable)**: When using the `path` to request the download, you

docs/user/reporting/script-example.asciidoc

@@ -3,7 +3,7 @@ The response from this request will be JSON, and will contain a `path` property
 URL to use to download the generated report. Use the `GET` method in the HTTP request to
 download the report.
 
-The request method must be `POST` and it must include a `kbn-version` header for Kibana
+The request method must be `POST` and it must include a `kbn-xsrf` header for Kibana
 to allow the request.
 
 The following example queues CSV report generation using the `POST` URL with cURL:
@@ -13,15 +13,14 @@ The following example queues CSV report generation using the `POST` URL with cUR
 curl \
 -XPOST \ <1>
 -u elastic \ <2>
--H 'kbn-version: {version}' \ <3>
+-H 'kbn-xsrf: true' \ <3>
 'http://0.0.0.0:5601/api/reporting/generate/csv?jobParams=...' <4>
 ---------------------------------------------------------
 // CONSOLE
 
 <1> `POST` method is required.
 <2> Provide user credentials for a user with permission to access Kibana and X-Pack reporting.
-<3> The `kbn-version` header is required for all `POST` requests to Kibana.
-**The value must match the dotted-numeral version of the Kibana instance.**
+<3> The `kbn-xsrf` header is required for all `POST` requests to Kibana.
 <4> The POST URL. You can copy and paste the URL for any report from the Kibana UI.
 
 Here is an example response for a successfully queued report: