curl --request POST \
  --url https://api.example.com/cabinet/admin/rbac/assignments \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "user_id": 123,
  "role_id": 123,
  "expires_at": "2023-11-07T05:31:56Z"
}
'

{
  "id": 123,
  "user_id": 123,
  "role_id": 123,
  "is_active": true,
  "role_name": "<string>",
  "user_telegram_id": 123,
  "user_username": "<string>",
  "user_first_name": "<string>",
  "user_email": "<string>",
  "assigned_by": 123,
  "assigned_at": "2023-11-07T05:31:56Z",
  "expires_at": "2023-11-07T05:31:56Z"
}