sorry, but I cannot find, where to test my uploaded Course. The link from the e-mail just opens the site for the course parameters. [:confused:][:confused:][:confused:]

You need to go to the My Courselab link, it is found on the left side menu area.
You need to log in and then you should have a few tabbed sections.
The modules do usually run exactly as you find during testing, the only oddities will be caused by the browser you are using.

thank you Nickj, it just wasnґt yet ready yesterday. Today it functions. But I can just one time test it, then there is a message: you already answered. So every user can only one time use the Course?

If you publish the module to CD then any restrictions you set (such as only allowing a single approach for a question or questions) will only apply while the module is open. Close it and start again and it is all reset.
These rules will persist only when you deliver the module through an LMS.