It looks as though one secret to getting published is simply finding the right publisher. There are many and their submission guidelines can be fairly specific.
Sadly I won’t be able to make wallpaper from rejection letters because everything is handled digitally, and most publishers say since they see hundreds or even thousands of submission every week, they take the “opt-in” approach of only writing those they intend to publish. Which is understandable.
Nonetheless the search begins. I’ve already found a small handful that seem like they might have interest and submitted one. Every journey with a single step, and all that.