The schema designer is designed to be used with the separate data hub application.
To use them together, follow the Data definition steps to define your data and sourcing rules, and generate the schema.
When the generate has completed, copy the text of the node options of the schemas in the schema designer folder at Schema Designer/Schema/Sources folder into files in the data hub schema folder. The standard place for this is /etc/datahub/schema. Use the reference to build the data hub file name, with an extension of .json. For example, if the reference is "sales", write the node option JSON to a file in /etc/datahub/schema/sales.json.
The default schema has a reference of "*". Write this to /etc/datahub/schema/default.json.
The DDL is available in the schema designer folder Schema Designer/DDL. This contains a separate page the DDL for each of the target tables. Apply this to the data hub database.
You may also need to configure the data hub itself, for example to secure which systems can send which data types. This is covered in the data hub documentation.