-------- |
| <code>id</code>      | integer/string | yes | The ID or <a href="rest/index.md#namespaced-path-encoding">URL-encoded path of the project or group</a> owned by the authenticated user |
| <code>email</code> | string | yes (if <code>user_id</code> isn't provided) | The email of the new member or multiple emails separated by commas. |
| <code>user_id</code>   | integer/string | yes (if <code>email</code> isn't provided) | The ID of the new member or multiple IDs separated by commas. |
| <code>acces