If an order comes into Finale through an integration and one of the defining attributes is a match to a customer that's already been configured in Finale, the system will automatically assign that customer to the order.
The attributes that are available to use for matching customers can be found in the task configuration of your "Pull sales to Finale" task. If you are pulling sales into Finale from more than one integration, it's best to ensure that the attributes are defined on each task.
The image below is an example from the ShipStation Pull Sales task configuration. You can define up to 3 total customer fields (in order of priority) for Finale to use and make a match with.
The available fields to use are:
Ship-to customer name
Ship-to company name
Bill-to customer name
Bill-to company name
Email address
If no matching customer is found based on the attributes you define, Finale will default to your integration configuration settings for mapping the customer. In this case, if you have opted to have all sales orders assigned to a common customer, ex: a customer called "Shopify" then that is what you can expect to see.
Otherwise, no customer profile will be added to the sales order automatically, but you do have the ability to add a customer profile to the sales order manually if you wish.