If you hear a rattling sound, the goal is to find the source, and tighten the loose component. Rattles are generally found due to loose fenders, or rear racks, so check these first.
Lifting the bike and dropping it a few inches off the ground (or one wheel at a time if it’s too heavy for you) is a great way to recreate the noise when you’re stationary, and you can then focus on the particular source of the noise and resolve the issue.
If you are still having trouble, please contact us to open a service ticket, and we can provide additional instructions as needed. You can also swing by your local Bicycle Shop to have them take a look and diagnose the source of the noise. This generally falls into the “bicycle stuff” category, so any shop can help us out.