curl --request PUT \
  --url https://api.xplenty.com/{account_id}/api/connection_groups/{connection_group_id} \
  --header 'Accept: <accept>' \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "connection_group": {
    "name": "<string>",
    "description": "<string>"
  },
  "connections": [
    {
      "id": 123,
      "type": "<string>"
    }
  ]
}
'

{
  "id": 123,
  "name": "<string>",
  "description": "<string>",
  "account_id": 123,
  "modified_by": {
    "name": "<string>",
    "email": "<string>"
  },
  "connections": [
    {
      "id": 123,
      "name": "<string>",
      "type": "<string>"
    }
  ],
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z"
}