Sorry about that. Here’s a link to the Auth0 React Quickstart that has the technique. Basically you use the getTokenSilently() method in the auth0-spa-js.
Tutorial: Auth0 React SDK Quickstarts: Call an API
GitHub: GitHub - auth0/auth0-spa-js: Auth0 authentication for Single Page Applications (SPA) with PKCE
getTokenSilently(): auth0-spa-js/Auth0Client.ts at 178b65f30c9b7a76ce762a1b4de1bd3ccfca5e5a · auth0/auth0-spa-js · GitHub