Hi

I've been trying everything I can think about,, and can't create a feature or a little thing on my part. I've tried to insert it as another part, but it won't work out.

I've sketched the feature (or thing or whatever to call it) in a seperate "part" just so it makes it easier to understand what my problem is, this has to be sketched in

the part named prototype where there is a hole in the same size. I really don't know how to create it in there :/

There has to 2 of those on each edge.

I've tried to illustrate it in paint too: