Once your discount is created, select "Go Live" from the action menu (3 dots) on the righthand side. Doing this will change the deal status to "Live", making it visible to your selected target audience.
Troubleshooting
Troubleshooting
Don't see the "Go Live" button? This means that the listing that your deal's under is unpublished (i.e. private).
Be sure to publish your listing from the listing action menu to enable the "Go Live" option for your deal.
No further action is needed once your deal is live. Your Partner(s) can now add them to their respective communities.