Your ad is not eligible for impressions because your listing is not in the

HI,
We´re new to Amazon and only have a handful of items listed so far.

We tried to advertise 2 items, but then i got this reply:

Your ad is not eligible for impressions because your listing is not in the buy box.

As we understand it takes 90 days for new sellers to get the buy box.

Does this also goes for items where we are unique and the only seller?

all the best!

It applies to all new sellers on a site.
Once you qualify you may get the buy box some of the time, most of the time or all the time. It’s kinda weird how the computer allocates it.