Image files are now supported for Signature Request's attachments

Only DOCX and PDF were previously supported as attachment formats in a Signature Request. To enhance flexibility, you can now upload PNG, JPEG, and JPG files as attachments.

Please note:

• These formats are for attachments only and cannot be signed.
• This feature is only available via API.

When uploading PNG, JPEG, or JPG files, you must specify the nature parameter to attachment in the following endpoints:

• Upload a document file (POST /signature_requests/{id}/documents/upload)
• Update a document (PATCH /signature_requests/{id}/documents/{document_id})

For more details, please refer to the guide section.