You did not mention what kind of recipe you want to copy. If you are trying to copy steps from a Prepare Recipe in one project to steps in a Prepare Recipe in a different project. See if this helps
The way this works is that the copy is putting a Json Description of the steps into your local computer's clipboard buffer. Then in the destination project you can paste those steps into an existing recipe that is already connected to datasets.
If you are trying to copy other kinds of recipes let us know. The challenge with copying recipes is that recipes know about their source and destination datasets. So copies can be a bit challenging.
That article says, "Of course, it is possible to copy the entire Prepare recipe, as with any visual recipe."
That's exactly what I don't know how to do - not between projects, anyway.