I-doit integration add user and password possibility

Hi there,
the i-doit integration works nice so far. I-doit has the abilitiy to change the language. I use zammad and i-doit in german translation. When I use the API just with the API token, I get the results in english. The i-doit support says in order to get translated results from the API, the i-doit user must be used. This user must be set to german to get the API results in german.
If I try the API endpoint http://apiuser:idoit@10.1.1.241/ it should work but it doesn’t do basic auth.
API says:
{“id”:null,“jsonrpc”:“2.0”,“error”:{“code”:-32604,“message”:“Authentication error : Setting ‘api.authenticated-users-only’ is enabled. Please provide valid user credentials by http basic auth or use an existing session id.”,“data”:null}}