apply postMessage

src/client/js/components/Admin/SlackIntegration/CustomBotWithoutProxySettingsAccordion.jsx

@@ -69,7 +69,7 @@ const CustomBotWithoutProxySettingsAccordion = ({
     setConnectionSuccessMessage(null);
     // TODO: 5921 Add new Test endpoint
     try {
-      const res = await appContainer.apiv3.post('/slack-integration-settings//without-proxy/test', {
+      const res = await appContainer.apiv3.post('/slack-integration-settings/without-proxy/test', {
         channel: testChannel,
       });
       setConnectionSuccessMessage(res.data.message);