Commonly, you'll go to list an item and find that Amazon restricts you from selling it.
When this happens, you'll get a popup message alerting you to the restriction.
First step is to request approval. The link will be in the popup message. Usually approval will be instant.
If you do not get approval, reject the item. This will remove it from the shipment. Set the item aside and either sell on another platform, dispose, or put aside until a future date when you may be allowed to sell it.
If you do get approved, click "Continue Listing" and add the item to your shipment.