Update NGINX Agent container instructions (#793)

Author: nginx-seanmoloney

content/nginx-one/agent/containers/run-agent-container.md

@@ -29,13 +29,10 @@ container image and create a configuration file.
 
 ### Pull the NGINX Agent container image
 
-The NGINX Agent container image must be downloaded from a trusted source such as Docker Hub or a private container registry.
-
 Run the following command to pull the official image:
 
 ```bash
-<!-- Registry HERE -->
-docker pull <Registry HERE>:latest
+docker pull private-registry.nginx.com/nginx-plus/agentv3:latest
 ```
 
 Ensure you are using the correct image version. Replace `latest` with the desired version tag if necessary.