ShipStation’s got a dedicated "Alerts" column on the Inventory Grid that’ll show you icons for stock that’s reached or fallen below a certain point!
Click on the Products tab.
Next, select Inventory from the sidebar on the left.
Now that you're at the Inventory Grid, look for the "Alerts" column. Any yellow warning icons mean that the stock has hit or fallen below the reorder threshold you defined.
Any red warning icons mean that the stock has fallen to zero.
You can enable the Alerts filter on this page to narrow your view to stock levels that have one of these alerts or no alerts at all.
You're also able to run an "Inventory Low Stock Report." Just head over to the Insights tab, and click Reports in the sidebar on the left. Scroll down to the "Inventory Reports" section and click Inventory Low Stock Report.