Sorry for my blindness, now I've seen what you mean. I've found the button. I used the German translated GUI.
But my real problem (creating a complete GPX file out of my founds) is not solved.
Is this feature only available for users who are paying members (I have a trial membership)?
I read on
https://project-gc.com/Home/Membership: Some notifiers are not available during trials
The message I mean is on
My Finds GPXs
If you check Automatically build My Finds GPX files on your settings page, the system will automatically build GPX files of your finds for you. (I checked it and after I saved it by clicking the button "Update settings")
A full GPX file of your finds will be built weekly, while an incremental version will be built daily.
My Finds GPX not available
My Finds Tiny GPX not available
Why does it happen?