I'd like to have a custom shortcut which will add the text "{{Wikidata Infobox}}" to a textbox in the active window. So far I've figured out to add Shift+W:i:k:i:d:a:t:a:Space:Shift+I:n:f:o:b:o:x, which correctly prints "Wikidata Infobox".

But how do I add the curly braces? I'm using a danish keyboard and to enter "{", I need to press the AltGr key + 7, so I've tried AltGr+7:AltGr+7:Shift+W:i:k:i:d:a:t:a:Space:Shift+I:n:f:o:b:o:x, but unfortunately that doesn't work and I have no idea how to find what else the AltGr might be named.

I would also like to print a Page Up key, but so far haven't had any luck with that either.

After digging through the source code behind the custom shortcut section (which is, if I am not totally mistaken, found in KHotkeys which then plugs into KKeyServer as the backend) I can say that there is no reference to AltGr anywhere in the code (compared to Shift which does appear) - which would explain why entering special chars in other keyboard layouts doesn't work. You could open up a bug report on bugs.kde.org. Alternatively, it should be possible to enter these characters via a DBus call, but I am no expert on DBus...