Implementing mapping in firebear module during migration

Question

I need to set up store id mapping during order migration. The firebear website has an example of how to set up mapping, but I don't understand how this method will understand that I want to change the store id.

https://firebearstudio.com/blog/manual-for-free-magento-1-to-magento-2-migration-add-on-for-improved-import-and-export-extension.html