Passing Encoded PAYLOAD data on URL during webservice load testing

I am trying to perform a load test and I have my Jmeter TestPlan as follow

Test Plan
|--Thread Group
|-------Authorizaiton Manager
|-----------CSV
|-------------HTTP Request Sampler
|----Listners

Under HTTP request Sampler
Server Name or IP:abc-atest.inf.com
Path:/pnpapp/services/smd/class/?PAYLOAD=${encodedData}
Method:Post

Under CSV
Filename: C:\loadTest\encodedPayload.csv
Variable Names:encodedData

When I run the testplan it gives me error