You have a data source for your B2B and B2C setup, this guide describes how to find each of them.

B2C

You find your b2c datasource by navigating to your company, clicking on data source in the menu and selecting the data source you want to edit.

B2B (Supplier only)

You find your b2b datasource by navigating to your inbox as a supplier, clicking the shortcut button and clicking data management in the menu.