Create a custom library by navigating to Project > System Settings > Libraries according to your customization levels.
Navigate to the library that you created and click the Library Configurator tab.
Create an object model folder in it by selecting New Object Model Folder menu option in the list that displays on clicking Add new object . Also, create an import rules folder by selecting the New Modbus Custom Import Rules menu option. For information, see Adding Blocks to a Library.
The library folder is created along with the Import Rules and Object Model folders.