What are the create bill API line item requiered fields

What are the create bill API line item requiered fields

While the following documentation says that the line items array is requiered it doesn't say what if any files are requiered in the array. Does anyone know? 


I'm trying to add fileds one at a time based on the failure messages which aren't clear either. For example {"code":13030,"message":"Item field under stock account cannot be empty."}
When there is no filed called "Item" in the API documentation.