Yes, epoxy on bare metal, then sandable primer (better known as "surfacer" in my opinion) on top of it. The surfacer should be applied within the epoxy time window for the specific epoxy you are using.
Depending on the depth of your imperfections, you may have to apply more coats of surfacer after sanding. You likely will sand most of the surfacer off. That's why surfacers are easy sanding. I don't like to leave any epoxy showing because I like to have a uniform color throughout before applying the topcoat.
Sand first with 220 grit and finish with 320 or 400 grit prior to topcoat. It is best to leave a uniform color shade that is as smooth as possible before topcoating. Any blemishes that you can see at this point will only be exaggerated after the topcoat is applied.