DOC-4307 Add DB availability API examples

Author: rrelledge

content/operate/rs/databases/durability-ha/db-availability.md

@@ -14,6 +14,32 @@ weight: 30
 
 You can use the [database availability API]({{<relref "/operate/rs/references/rest-api/requests/bdbs/availability">}}) to verify whether a Redis Software database is available to perform read and write operations and can respond to queries from client applications. Load balancers and automated monitoring tools can use this API to monitor database availability.
 
+## Check database availability
+
+To check the availability status of a database:
+
+```sh
+GET /v1/bdbs/<database_id>/availability
+```
+
+If the OSS Cluster API is enabled, this request verifies all endpoints for this database are available. Otherwise, it verifies the database has at least one available endpoint.
+
+Returns the status code 200 OK if the database is available.
+
+If the database is unavailable, returns an error status code and a JSON object that contains [`error_code` and `description` fields]({{<relref "/operate/rs/references/rest-api/requests/bdbs/availability#get-db-error-codes">}}).
+
+## Check local database endpoint availability
+
+To check the availability of a local database endpoint:
+
+```sh
+GET /v1/local/bdbs/<database_id>/endpoint/availability
+```
+
+Returns the status code 200 OK if the local database endpoint is available.
+
+If the local database endpoint is unavailable, returns an error status code and a JSON object that contains [`error_code` and `description` fields]({{<relref "/operate/rs/references/rest-api/requests/bdbs/availability#get-endpoint-error-codes">}}).
+
 ## Availability by database status
 
 | Database status | Availability |