Yes, ecomdash and ShipStation work side by side. There is no extra connection needed for the two to work together seamlessly!
As ecomdash imports your sales orders and maintains the quantity on hand for your marketplaces, ShipStation will also import the order so that you can work the order as you normally would out of ShipStation.
Ecomdash will see that the status of the order has changed from unshipped to shipped on the sales channel and move the order to complete within ecomdash.
If one of your storefronts is integrated with ShipStation but ecomdash does not support that storefront as an integration, you can add ShipStation as a Sales Channel.
If one of your Sales Channels is not integrated with ShipStation, you can add ShipStation as a warehouse.
Note: You cannot have ShipStation setup as both a Storefront and Warehouse within your ecomdash account.