Yeah, the correct term is "bonapartist" which is also a pretty established and defined term, just libs don't give a shit when they can just slap "authoritarian" and immediately exchange it for any other term for "bad" their neurons can produce.
The term fascism didn't appear until nearly a century after Napoleon died. It would be like saying John Lilburne was a socialist.
Calling Napoleon a fascist would also open a big bucket of worms that would place nearly every European monarch under that label. It's imprecise and ahistorical. The best definitions of fascism place it as an emergency condition of capital, where the tools of imperialism are turned inward to suppress leftist movements, and this is done among popular enthusiasm. The thing most suppressed by Napoleonic code was aristocracy, not internal leftist movements. The conditions that were administered by the First French Empire were barely at the beginning stages of capitalism even existing.