How to run data factory pipeline using WebActivity/Rest using optional uri parameter e.g isRecovery?

Hi , 

I can to execute  a pipeline in data factory using Web activity /Rest API.   

I am trying to rerun a pipeline in data factory from the failure activity using Web activity/Rest API. 

As per the documentation I have to pass IsRecovery , referencePipelineRunId and startFromFailure uri parameters.  

I am doing it , but a new run is generated for the pipeline instead of starting from failure activity. These optional parameters are not recognized correctly. 

May be, I am not able to pass the these optional parameter values in correct format.  How to pass boolean uri parameters IsRecovery , startFromFailure ?  Any example uri with these optional parameters would help me.