Can someone tell me if it is possible to preview a backround in your story that is not yet approved?
yes you just uploade them and put them in the script, ther will come a red arrow message but it just say you cant publish before its approved, you can still code with it.
yes but i cannot see it to preview how it would look
You can preview it. Any backgrounds and overlays that you upload, are instantly viewable on both the portal previewed, and if you preview on your device even if they aren’t approved yet.
The only thing that won’t work is publishing the episode with an unapproved background.
So if you are unable to see it in the previewed, I can only presume that you’ve made a coding error, or there’s a glitch on your computer.
You can also preview it by clicking on the picture in the background overlay upload section. Hope it helps
Moved to Creator’s Corner since this is about story creation. Make sure to check out our Forum Tutorial for more info about creating topics, and feel free to PM me if you’ve got questions. 
In addition to what Cheyara said, your backgrounds will not be visible on your previewer (in app or portal) if they get rejected.
What I do when I code is I have one tab for the script and another tab for the art catalog (where the overlays and backgrounds are) and I can use my second tab to have a look at my backgrounds and decide which one I want to use, so I copy and paste the name of it into the script in the first tab. For a closer look at your backgrounds and overlays, you can click on them in the art catalog and they pop up in a bigger size.
If you just uploaded them into the art catalog and they aren’t appearing there, try refreshing your page and searching them using the name(s) you uploaded them with.