Python -recurring payment - Access to OffAmazonPayments_Sandbox.ConfirmBillingAgreement is denied

[arjsp]

When I try to setBillingAgreementDetails after a recurring payment , I am getting this error - { "ErrorResponse": { "Error": { "Type": "Sender", "Code": "AccessDenied", "Message": "Access to OffAmazonPayments_Sandbox.ConfirmBillingAgreement is denied" }, "RequestID": "f3449e85-c415-4177-b4e7-e7d4628ed4d4" } }

How to resolve this?