If you get this message "Ad account has no access to this Instagram account. Please use an authorized Instagram account or assign ad account to this Instagram account first" it means you need to assign your Instagram account to the ad account you want to run ads with.

Here is how you do it:

Once it's added, hard refresh the page on Smart Noise. If the Instagram account still doesn't show up, try logging out and back in your Facebook profile on Smart Noise.