Ipad Pro -> external keyboard -> no @ sign - and no keyboard will be shown

I am using an Ipad pro with an external keyboard (German layout).

The @ sign is on the L key.  On the IPAD, I get the @ sign with the "Option" key + "L" key.

If I log into a Windows Terminalserver, no way to get the @ sign.

So I tried to get the @ sign over the Jump Desktop virtual keyboards. But there is no way to get the normal Jump Desktop keyboard.

When I click on the right/ left upper corner, the JD keyboard list will be shown. Depends on what I select. 123 or F1 .. or.. But .. I can't select the normal keyboard. Why ?

Regards

Stefan