integration of Appian workflow with DocuSign

Thanks Tyler, It did fix the issue related to expression but I guess removing[] another issue. When I ran the process, It got completed but got following error on output:

{ "errorCode": "INVALID_REQUEST_BODY", "message": "The request body is missing or improperly formatted. Cannot deserialize the current JSON object (e.g. {\\"name\\":\\"value\\"}) into type 'API_REST.Models.v2.document[]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.\\r\
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.\\r\
Path 'documents.documentId', line 1, position 98."}

Thanks Tyler, It did fix the issue related to expression but I guess removing[] another issue. When I ran the process, It got completed but got following error on output:

{ "errorCode": "INVALID_REQUEST_BODY", "message": "The request body is missing or improperly formatted. Cannot deserialize the current JSON object (e.g. {\\"name\\":\\"value\\"}) into type 'API_REST.Models.v2.document[]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.\\r\
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.\\r\
Path 'documents.documentId', line 1, position 98."}