Automatically re-login if already authenticated in SPA using Refresh Tokens

If a user has already been auththenticated with the auth0.loginWithPopup and then they exit the website without logging out, how do you authenticate them automatically without having them click the login button? Below is my website startup page code:

domain: Settings.auth0_domain,
clientId: Settings.auth0_clientId,
useRefreshTokens: true,
authorizationParams: { audience: “https://” + Settings.auth0_domain + “/api/v2/”, scope: “openid profile email offline_access” },

}).then(auth0Client => {
//User is not authenticated at this point even though they have previously logged in?
//What goes here? Do I need to use loginWithRedirect and store the tokens in local storage?

}).catch((error: Error) => {