We'd like to have a bearer token configuration that is more flexible than the current `bearerTokenLocalStorageKey`, for example, by allowing a custom function to retrieve the bearer token. Our app uses [@axa-fr/react-oidc](https://github.com/AxaFrance/oidc-client/tree/main/packages/react-oidc), which stores the access token within a JSON object in local storage, not a simple string. This is not supported by `bearerTokenLocalStorageKey`. <img width="386" height="27" alt="Image" src="https://github.com/user-attachments/assets/cf119863-0cbe-43f9-99d4-2d4d429426b6" />