Get the installation command for a Direct Access Agent (DAA) collector. The command is encoded in base64 and must be decoded before execution — for example: base64 -d <<< "cG93...". To retrieve the coreId, see Create a new Virtual Site Collector instance. To retrieve templateIds, see Create a new Site Collector template. For other operations such as update, upgrade, stop, restart, and delete, use the Update a Site Collector agent, Upgrade, Stop, Restart, and Delete endpoints.