Feat: Improve embed panel info text (#16344)

* improving documentation for Embed Panel

Fixes #16345

docs/sources/reference/sharing.md

@@ -57,6 +57,7 @@ http://play.grafana.org/render/dashboard-solo/db/grafana-play-home?orgId=1&panel
 ### Embed Panel
 
 You can embed a panel using an iframe on another web site. This tab will show you the html that you need to use.
+> *Notice* This sharing require either anonymous access or setting [cookie_samesite]({{< relref "installation/configuration/#cookie-samesite" >}}) to none
 
 Example:
 

public/app/features/dashboard/components/ShareModal/template.html

@@ -31,18 +31,21 @@
 			<i class="fa fa-code"></i>
 		</div>
 		<div class="share-modal-content">
-			<p class="share-modal-info-text">
-				The html code below can be pasted and included in another web page. Unless anonymous access
-				is enabled the user viewing that page need to be signed into grafana for the graph to load.
-			</p>
-
 			<div ng-include src="'shareLinkOptions.html'"></div>
 
-			<div class="gf-form-group gf-form--grow">
+      <p class="share-modal-info-text">
+			 The html code below can be pasted and included in another web page. Unless anonymous access
+			 is enabled, the user viewing that page need to be signed into grafana for the graph to load.
+       Grafana server setting <code>cookie_samesite</code> might also need to be changed to support login
+       inside an iframe.
+			/p>
+
+      <div class="gf-form-group gf-form--grow">
 				<div class="gf-form">
 					<textarea rows="5" data-share-panel-url class="gf-form-input" ng-model='iframeHtml'></textarea>
 				</div>
 			</div>
+
 		</div>
 	</div>
 </script>