Composite Template with inline template

Hi guys 

I am developing Send Envelope Programs on SAP system 

we using docusign API and My client wants to

automatically send purchase orders, contract terms, and quotations to their supplier representatives with each document attached. These attachments are stored in SAP as base64-encoded data.

My client wants to use anchor-based signing for purchase orders, and initial-based signing for the remaining contract terms and quotations, placing initial signatures at both ends of the documents for the purchasing manager and the supplier's seller. (I will only use inline Templates )

I developed the program using signHere tabs for the anchor method and initialHere tabs with specified positions for the initial method, but I received the following message:

"The Envelope is not Complete. A Complete Envelope Requires Documents, Recipients, Tabs, and a Subject Line."

Could you take a look to see if my API request/response structure is wrong? I am really desperate, and I would appreciate the opinions of skilled API developers.