The beard needs a certain length, then it works

I'm not sure about the beard, you can try it because my hair isn't 100% straight

Yes, I also bought it for the beard. If the beard is long and thick enough, it works. From a length of approx. 7cm.

The disadvantage of the smoothing brush is that it is made for long hair and so the heating elements are almost too far apart. As a result, you don't get close enough to the skin, which means that the hair on the face is still a bit tousled. I've done it a few times, but the beard suffers a little from the heat.
However, if you have a really long beard, it certainly works well.