add faq (#4531)

adding faq to help users solve 403 service token error [per slack
thread](https://dbt-labs.slack.com/archives/C04H4G1NET0/p1700587758226669).

website/docs/docs/dbt-cloud-apis/service-tokens.md

@@ -115,3 +115,5 @@ To rotate your token:
 4. Copy the new token and replace the old one in your systems. Store it in a safe place, as it will not be available again once the creation screen is closed.
 5. Delete the old token in dbt Cloud by clicking the **trash can icon**. _Only take this action after the new token is in place to avoid service disruptions_.
 
+## FAQs
+<FAQ path="Troubleshooting/ip-restrictions" />

website/docs/faqs/Troubleshooting/ip-restrictions.md

@@ -0,0 +1,29 @@
+---
+title: "I'm receiving a 403 error 'Forbidden: Access denied' when using service tokens"
+description: "All service token traffic is now subject to IP restrictions. To resolve 403 errors, add your third-party integration CIDRs (network addresses) to the allowlist."
+sidebar_label: 'Service token 403 error: Forbidden: Access denied'
+---
+
+
+All [service token](/docs/dbt-cloud-apis/service-tokens) traffic is subject to IP restrictions.
+
+When using a service token, the following 403 response error indicates the IP is not on the allowlist. To resolve this, you should add your third-party integration CIDRs (network addresses) to your allowlist.
+
+The following is an example of the 403 response error:
+
+```json
+        {
+            "status": {
+                "code": 403,
+                "is_success": False,
+                "user_message": ("Forbidden: Access denied"),
+                "developer_message": None,
+            },
+            "data": {
+                "account_id": <account_id>,
+                "user_id": <user_id>,
+                "is_service_token": <boolean describing if it's a service token request>,
+                "account_access_denied": True,
+            },
+        }
+```