Click 
(Execute icon) or to run the job remotely, click Execute Remotely in the Options tab.
Executing a third-party tool object remotely sends the job to the server that is defined in the Preferences dialog (Edit > Preferences > Remote Execution).
The project must have been saved at least once prior to executing on RPS, otherwise execution will not pass validation and a message will be generated.
At this point, the step being executed on RPS and any dependent objects, are locked. It is now safe to close the project or to continue working in Phoenix.
In Phoenix, some objects in a workflow, when executed and the last object in a chain, will re-run any necessary objects earlier in the workflow. This is not true for the R object. Either the workflow or the individual objects must be executed to obtain the current source data for the R object.