Passing values in json format

Hi All,

I have a requirement where i have to pass the value from variable into the webapi . I am receiving 500 error as the following code is not in Json format.

|post web api | testWebapi | with body |{"var1":tv!variable} |with username| testUsername

Did anyone of you face similar issue and how do we pass the tv!variable in Json Format.

Thanks In advance

Regards,

Sahithi