Hi! Welcome to Numista and welcome to the forum.
Your note seems to be this one, the variant with an 8 digit number:
N#202198
The gothic script isn't always easy to read, but the note actually reads Hundert Mark, ‘100 Mark’.
I'm not an expert to judge if it is authentic or not, but it doesn't seem to be a very expensive note, which reduces the chance that it's fake.
Enjoy collecting!