First you'll need a gun.deals account. If you don't already have one you can go to https://www.ammoready.com/slickguns
If you sign up through AmmoReady you get a discounted price for gun.deals of $199
Once you have an account with them you can turn on your feed on AmmoReady under Settings > Store.
You will need to check that box, then check the boxes for what to include in the feed.
Then you will need to copy the URL that is in the dark grey box and send that to gun.deals and request they turn on your feed.