Hi,
We received a bonsai from Ikea as a gift and it's losing quite a lot of it's leaves.
First they get some small black dots and then they fall, even if they are still green.
You can see in photo "initial" how it looked when we brought it home and in the "after" photos how it looks now, including the black dots on the leaves.
I'm not an expert, so would very much appreciate if you know what's happening and what do I have to do to save it.
Thank you in advance!

Hello and welcome.
You do know this is the dutch speaking forum?
You didnt add any pictures but coming from Ikea you probably bought a ficus ginseng which is really not a bonsai ( its the roots of one ficus where another type of ficus is grafted on). Just do with it what you would do to every other houseplant.
If its another tree, just upload a picture and we'll go from there