Sending multiple documents to a single signer

​@NoselessWonder A Docusign envelope contains one or more documents. Each document contains one or more pages.
It is possible to send an envelope that has multiple documents. You can also define a document ID for each individual document and this is how you can track them via the Webhook payload.
When configuring Docusign Connect you’d want to use the “REST v2.1” data format and ensure “Documents” is selected under the “Include data” section. You’d also want to select the envelope event ‘Envelope Signed/Completed”. 

An example create envelope request would look like the following: 
 

{
	"status": "Sent",
	"emailBlurb": "TestValue",
	"emailSubject": "Please DocuSign: Text (1).pdf",
	"recipients": {
		"signers": [
			{
				"deliveryMethod": "email",
				"recipientType": "signer",
				"routingOrder": "1",
				"recipientId": "1",
				"email": "example@gmail.com",
				"name": "firstName lastName",
				"tabs": {
					"textTabs": [
						{
							"pageNumber": "1",
							"xPosition": "352",
							"yPosition": "249",
							"name": "enterText",
							"documentId": "1"
						}
					]
				}
			}
		]
	},
	"documents": [
		{
			"display": "inline",
			"documentBase64": "DocumentBase64GoesHere",
			"documentId": "1",
			"includeInDownload": "true",
			"name": "Text (1).pdf",
			"order": "1",
			"pages": "1"
		},
		{
			"display": "inline",
			"documentBase64": "DocumentBase64GoesHere",
			"documentId": "2",
			"includeInDownload": "true",
			"name": "Text (2).pdf",
			"order": "2",
			"pages": "1"
		}
	]
}

The Connect payload would return you with the documents and their ID’s as well. 

If you’re sending using templates the same idea would apply and the below resources provide additional examples: ​​​​​​​
https://developers.docusign.com/docs/esign-rest-api/how-to/request-signature-template-remote/
https://developers.docusign.com/docs/esign-rest-api/esign101/concepts/templates/composite/