Securing access between services is crucial for enterprises with multiple integrated applications and services that need to communicate and share data. The new integration with Auth0 by Okta enables Netlify users to manage access across multiple services securely, providing a streamlined solution for managing access across complex application architectures involving multiple teams and departments. This integration allows developers to automatically link their sites to Applications and APIs on Okta and add authorization to Netlify Functions using the `withAuth0` method, enabling the creation of SaaS applications on Netlify. The integration also provides an example using the Auth0 SDK for React Single Page Applications, which uses environment variables such as `AUTH0_CLIENT_ID` and `AUTH0_DOMAIN` to configure authentication with Auth0. Additionally, developers can use the `withAuth0` hook in serverless functions to add authorization, requiring authentication and possessing a specific role, such as admin, to access protected resources.