When you say "the underside of the typewriter," do you mean the drawband is attached to the underside of the carriage (i.e. the assembly that moves to the left as you type)? I am not familiar with this model, but typically, the drawband on a typewriter is attached to the underside of the right side of the carriage, and is attached on the other end to the edge of the typewriter's mainspring. The mainspring is an enclosed unit, mounted vertically underneath the carriage on the left side, and is in the shape of a disc or wheel. Others can describe this a lot better than I just did, or have pictures to illustrate this.  But look for the mainspring assembly, and you should be able to find a hook or notch where the drawband attaches.

Hi, thanks for your replies. I would love to see other Kolibris underneath, to see if they are similar.
The drawband was not broken just disconnected. I've now managed to attach it to both sides i.e on the underside of the right side of the carriage and beneath the typewriter at what I assume is the mainspring (a circle thing). My problem now is I've got no clue as to how I should be supposed to wind up this mainspring.

Check the mainspring "(a circle thing)" to make certain it has tension. You can test it by rotating it slightly then release it. It should spring back when released. If the mainspring doesn't spring back (have tension) then you need to repair/replace that before worrying about drawband/drawstring attachment. If it does have tension, then you need to turn it a couple of times then attach the band/string.

Do know, you may need an extra pair of hands and a lot of patience. My first repair took forever until I got the concept. After, it was pretty easy. Google this repair so that you can get the mechanical concept behind the repair, even it it's not for your model.

I won't have access to my friend's machine for a few weeks or photos .. sorry