There are three options for how to run the business processes:
Send all sales orders to ShipStation as the orders are created.
Use this if you are operating a high volume, short delivery time business such as fulfilling standard products. Your sales orders will be visible in ShipStation immediately and it will be up to warehouse staff (ShipStation users) to decide what to ship and when.
Create the sales dispatch in Manu Online and transfer it to ShipStation.
Use this option if you are selling products with a lead time and want to choose which products to ship and when based on data available in Manu Online.
Create a direct sales in Manu Online when orders are shipped in ShipStation
Use this if you have your e-commerce system connected to ShipStation and you do not want to litter your ERP system with large numbers of one-off customer names and addresses. Use Manu Online to control batch manufacturing, perhaps against sales forecasting, and refill stock quantities from production work orders.
In either of these cases ShipStation may be in-house or being used a 3rd party fulfilment service. The business processes are the same but the users and locations may the same or different.
To use these integrations, make sure that you have a Zapier account at a level suitable to run multiple step Zaps.