curl --request POST \
  --url https://api.bundleup.io/v1/connections \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "integration_id": "<string>",
  "auth_token": "<string>",
  "external_id": "<string>",
  "refresh_token": "<string>",
  "expires_in": 123
}
'

{
  "data": {
    "id": "<string>",
    "external_id": "<string>",
    "expires_at": "2023-11-07T05:31:56Z",
    "integration_id": "<string>",
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z"
  }
}