The given configuration for the Open Commerce API (OCAPI) allows only GET requests to the /baskets/** resource, which permits reading basket data but does not allow modifying it, such as adding products to a basket. To successfully execute requests that modify the basket, such as adding items, the methods attribute needs to include POST. Changing the methods value to ["get", "post"] will allow both retrieving and modifying basket data. This is consistent with the typical usage of HTTP verbs where GET is used for retrieving data and POST is used for submitting data to be processed, as outlined in the Salesforce B2C Commerce documentation on configuring OCAPI.