Looks like the JMA AS-KK7 Key Blank.
Equivalents:
Orion: A35KK
Errebi: AA91
C Birch: AS74
Silca: ASS109
As you're in Denmark, I'd suggest calling around some local locksmiths, see if they can supply you with some blanks. Assa blanks are heavy steel, so have a good quality round file.
Yes, you can create a key with this being picked, but it's not something I'd recommend to a novice. But saying that, it would be fun and you'd learn a whole lot in the process. Once picked, look down the hole where the shackle goes and you'll see a screw. Remove that, and the core will drop out.
Once done, remove the clip off the back of the core and slid out the plug using a plug folllower (rolled up business card will do the trick). You just need the plug and all it's key pins for the key creation.
Now insert the blank key into the plug, and the key pins will all be visible. Use the longest one to press down hard on the key blank in each of the key pin positions. You now have marks on the key blank giving the correct spacings. Mark them with a permanent pen.
Now progressively file down in those spacings until the key pins are exactly flush with the surface of the plug. You will then have a correct key.
Reassemble, pat yourself on the back, and have a nice day