You don’t do anything. You have a licence to operate in Germany. See section 16 of the paper licence you were sent when lifetime licences were brought in. Or look at the PDF version of your licence you downloaded.
Hi John, you just have to remember to adhere to that particular Countries rules, for example if in Germany no /m or /p operation on 6m, and some countries used to have no tx above 7.1Mhz on 40m although I think these may all have changed now. Listen out for me & GW0DSP from Germany next month. We may also stray into ON & LX as well.
73.