Thank you for the answer. But as usual the documentation really needs more attention.

Here for example:

• On this page (https://unacms.com/wiki/Dev-API) the authentication methods are described with an example how to add an entry using the posts module.
• A List with safe and unsafe services is not there.

I'm trying now for hours to create one event using the api and got already a few hundred times "HTTP 404" because I just don't find the correct value for "r=".

I've found a "insert"function in BxEventsFormEntry.php, but it can not be called from the api.