Can I add my own genre to my story?

I started to submit a story but backed off when I couldn't find a genre I liked in the list. But today I saw a story with a bunch of genres listed, many of which aren't in the list. How did they do that?

Those aren't genres. Those are tags. You get one genre and then use tags to spell out other significant elements of the story so people interested in and searching for those elements can find them.

So pick the genre that is the best fit and then tag for subgenre, story elements, kinks, etc. that might help people who would be interested in your story find it.

There's a bit of marketing involved, too. Some genres clearly attract more eyeballs than others.

And, of course, if blood relatives are involved, then you must use Fantasies as the genre.

Thanks. This helps.