This is such a solvable problem.
Doesn't package.json have an is private repo flag? Why not just respect that?
Why does everyone everyone in this thread think a pop up is the solution?
Pop ups are a code smell. They mean your application does not correctly match user intent with the action so badly you had to specifically get your user to tell you what they meant to do. Did you mean to do that? Always, yes. Otherwise, undo.
The only place did you mean makes sense is in Google search results.
Why is public and private publish anywhere near each other? Why are they even on the same page?
Stop drawing boundaries around nouns.