add tracks event for emails subscription

client/performance-profiler/pages/weekly-report/index.tsx

@@ -2,6 +2,7 @@ import { useTranslate } from 'i18n-calypso';
 import { useEffect } from 'react';
 import DocumentHead from 'calypso/components/data/document-head';
 import { useLeadMutation } from 'calypso/data/site-profiler/use-lead-query';
+import { recordTracksEvent } from 'calypso/lib/analytics/tracks';
 import {
 	MessageDisplay,
 	ErrorSecondLine,
@@ -21,6 +22,15 @@ export const WeeklyReport = ( props: WeeklyReportProps ) => {
 		mutate();
 	}, [ mutate ] );
 
+	useEffect( () => {
+		if ( isSuccess ) {
+			recordTracksEvent( 'calypso_performance_profiler_emails_subscribe', {
+				url,
+				hash,
+			} );
+		}
+	}, [ isSuccess, url, hash ] );
+
 	const secondaryMessage = translate(
 		'You can stop receiving performance reports at any time by clicking the Unsubscribe link in the email footer.'
 	);