Update Braze identifiers

Update Braze identifiers

Author: niallzato

src/connections/destinations/catalog/braze-cloud-mode-actions/index.md

@@ -44,3 +44,8 @@ Braze Cloud Mode (Actions) provides the following benefit over Braze Classic:
 
 Keep the following in mind if you plan to move to Braze (Actions) from the classic Braze destination.
 {% include components/actions-map-table.html name="braze-cloud" %}
+
+## Troubleshooting
+
+### Missing required fields
+Braze require one of "external_id" or "user_alias" or "braze_id" to be present in all events sent. If events are faileing to send, please chcek your event mappings to make sure these fields are resolving to valid values.