As per Amazon's documentation, we advise checking with the restock Inventory page and restock report in Seller Central so you can check which products are eligible for shipment creation.
US/MX/CA sellers: https://sellercentral.amazon.com/gp/help/help.html?itemID=GF37V7QBB8WSVF43
UK/DE sellers: https://sellercentral.amazon.co.uk/forums/t/covid-19-update-on-prioritised-shipment-creation-new-tool-to-check-eligibility/280094