Your API token is required so the script can have access to the database of your project and be able to update your collection items.
Here's how to get it
Select here the website you would like to work with. This is the website that holds the collection lists you want to link together.
Select here the collection list you want to work at.
Select here the field that you created as a text field when importing the CSV. This is the field that should hold the text that references another collection's items.
Select here the reference field that should be updated by the script. This reference field must point to a valid collection list.
The information below will be used to perform the update of each item. They are references to items available on the collection list that is the target for the reference field selected above.