You need to configure the template and add your input object and the row object.

Take a look at the documentation for more details:

https://docs.mendix.com/appstore/modules/excel-importer

Additionally, the objects (rows of your excel) would either be stored in a persistent entity or a non persistent one depending on how you configured. You could do a retrieve to get those objects, do note that for retrieving from a non persistent entity you’d need an association to do so.

Hope this help!