Controlling user access to documents with tokens in kendra

I am trying to control user access to documents with tokens in kendra as this link suggested "https://docs.aws.amazon.com/kendra/latest/dg/create-index-access-control.html". I have created JWT Shared Secret Key but when i give this key to the Amazon Kendra Indexes search it saying wrong token. In my token no '. ' is present. please help me how to do user access to documents with tokens in kendra