How to register S-Pedalec in EU / Germany?

Hello,

years back I believe someone has shared their experience of getting their home built S-Pedalec in Germany (45km/h)? Can't find the thread anymore - has anyone have it at hand?

Thanks!
Wojtek

https://endless-sphere.com/forums/viewtopic.php?f=6&t=52895

(it's not a s_pedelec but a L1e-B "moped"). Today this could be similar, but back than s-Pedelec have been classified as L1e-A. (since 1.1.2017 they are L1-e B, too)