I'm unable to apply price group to cart

Summary:

We are developing an app using the occ apis.
We are having difficulty applying the price to the cart with a specific price group for the application. The list name is "APP". When browsing, we are able to apply the correct price, but when adding the item to the cart, it takes the default price list.

We're doing everything via the REST API. Someone has already implemented the request because we're following the documentation, and the price isn't being applied.

Version (include the version you are using, if applicable):

OCC Version 25.06