Include the appropriate endpoint that supports the authorization,create_payment_token or sale,create_payment_token transaction types (see Endpoints and Transaction Types). For descriptions of all request and reply fields, see API Fields.
The amount field is an optional field that indicates the setup fee for processing recurring payments. To charge this fee, include the amount field and ensure that the transaction_type field is set to authorization,create_payment_token or sale,create_payment_token.
signed_field_names=comma separated list of signed fieldsunsigned_field_names=comma separated list of unsigned fields
signed_field_names=comma separated list of signed fields