Before adding a document, you may have to add placeholders for each signer.Documentation Index
Fetch the complete documentation index at: https://signatureapi-daf4ee54.mintlify.app/llms.txt
Use this file to discover all available pages before exploring further.

Input
The file content of the document. Learn about some common File Content sources.
The ID of the envelope to which the document will be added.
The title of the document. It may be shown to recipients.
Extra properties for extensibility.
Output
The ID of the document.