Signing sender documents by API

Hi, We have been trying to sign all documents using the canadian REST API (e-signlive.ca/api) We tried creating a package with the code provided on https://developer.esignlive.com/guides/feature-guides/sign-documents/ . We added a role ('Sender') and approval for this role.

{
  "name":"Contract B J R",
  "description":"",
  "roles":[
     {
        "id":"SignerContract",
        "type":"SIGNER",
        "signers":[
           {
              "firstName":"B J",
              "lastName":"R",
              "email":"[email protected]",
              "delivery":{
                 "email":false
              },
              "auth":{
                 "scheme":"NONE"
              }
           }
        ]
     },
     {
        "id":"Sender",
        "type":"SIGNER",
        "signers":[
           {
              "firstName":"sender.firstname",
              "lastName":"sender.lastname",
              "email":"[email protected]"
           },
           {
              "auth":{
                 "scheme":"NONE"
              }
           }
        ],
        "name":"Sender"
     }
  ],
  "documents":[
     {
        "name":"Contract",
        "id":"Contract",
        "approvals":[
           {
              "role":"SignerContract",
              "fields":[

              ]
           },
           {
              "role":"Sender",
              "fields":[

              ]
           }
        ]
     }
  ],
  "settings":{
     "ceremony":{
        "inPerson":false
     }
  },
  "visibility":"ACCOUNT",
  "type":"PACKAGE",
  "due":null,
  "autocomplete":true,
  "emailMessage":"",
  "status":"DRAFT",
  "language":"nl"
}

Sending a POST to /api/packages/{packageId}/documents/signed_documents (using API key)

{
  "documents":[
     {
        "id":"Contract",
        "name":"Contract"
     }
  ]
}

Results in 200 OK response without content, but it doesn't seem to sign anything (for any recipients). What should we be doing?