Add FAQ and Troubleshooting Section to FB CAPI (Actions) doc (#2461)

* Add FAQ and Troubleshooting Section to FB CAPI (Actions) doc

* Update src/connections/destinations/catalog/actions-facebook-conversions-api/index.md

Co-authored-by: markzegarelli <[email protected]>

* Update src/connections/destinations/catalog/actions-facebook-conversions-api/index.md

Co-authored-by: markzegarelli <[email protected]>

* Apply suggestions from code review

Co-authored-by: stayseesong <[email protected]>

Co-authored-by: markzegarelli <[email protected]>
Co-authored-by: stayseesong <[email protected]>

Author: 3 people

src/connections/destinations/catalog/actions-facebook-conversions-api/index.md

@@ -119,8 +119,30 @@ You can send additional User Data to increase the match rate for events from a s
 
 If you choose this option, each source sends different events, and deduplication is not necessary.
 
+## FAQ & Troubleshooting
 
-## Verify Events in Facebook
+### Other Standard Events
+
+If you want to send a [Facebook standard event](https://developers.facebook.com/docs/meta-pixel/reference#standard-events){:target="_blank"} that Segment does not have a prebuilt mapping for, you can use the [Custom Event action](/docs/connections/destinations/catalog/actions-facebook-conversions-api/#custom-event) to send the standard event. For example, if you want to send a `CompleteRegistration` event, create a mapping for Custom Event, set up your Event Trigger criteria for completed registrations, and input a literal string of "CompleteRegistration" as the Event Name. You can use the Custom Data key/value editor to add fields that are in the `CompleteRegistration` event such as `content_name` and `currency`.
+
+### PII Hashing
+
+Segment creates a SHA-256 hash of the following fields:
+- External ID
+- Email
+- Phone
+- Gender
+- Data of Birth
+- Last Name
+- First Name
+- City
+- State
+- Zip Code
+- Country
+
+If you use Facebook Pixel, the Pixel library also hashes the External ID. This means External IDs will match across Facebook Pixel and Facebook Conversions API if they use the External ID for [deduplication](https://developers.facebook.com/docs/marketing-api/conversions-api/deduplicate-pixel-and-server-events/#fbp-or-external-id){:target="_blank"}.
+
+### Verify Events in Facebook
 
 After you start sending events, you should start seeing them in twenty minutes. You can confirm that Facebook received them: