Update migration-api-overview.md (SharePoint#4481)

Content update:  Added sample on how to call the API through REST.

Author: JoanneHendrickson

docs/apis/migration-api-overview.md

@@ -1438,6 +1438,23 @@ There is no change from current published full 2013 [full 2013 package schema](h
 
 There is no change from current published [full 2013 package schema](https://docs.microsoft.com/en-us/sharepoint/dev/schema/content-migration-schemas).
 
+## Sample: Using REST to call the API
+
+
+https://<spam><spam>yourtenanthere.sharepoint.com/sites/importSite/_api/site/CreateMigrationJobEncrypted<spam><spam>
+ 
+{
+    "options": {
+        "AES256CBCKey": "000000000000000000000000000000000000000000000000000000="
+    },
+    "gWebId": "00000000-0000-0000-0000-000000000000",
+    "azureContainerSourceUri": "https://<spam><spam>tenant.blob.core.windows.net:443/00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000<spam><spam>=rw",
+    "azureContainerManifestUri": "https://<spam><spam>tenant.blob.core.windows.net:443/00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000<spam><spam>=rw"
+}
+ 
+For the container
+https://<spam><spam>yourtenanthere.sharepoint.com/sites/importSite/_api/site/ProvisionMigrationContainers<spam><spam>
+ 
 
 >[!NOTE]
 >The **Migration API** is not available for users of Office 365 operated by 21Vianet in China. It is also not available for users of Office 365 with the German cloud using the data trustee, *German Telekom*. However, it is supported for users in Germany whose data ___location is not in the German data center.