Flutter and Auth0

Hi Guys we are very close to getting this right but now just need to find out how to add the expiry of a token in the request. Currently we are able to log in but the token expired immediately.

var user = await auth.passwordRealm(
        username: "yours@email.com",
        password: "**********",
        scope: "openid profile",
        realm: "Username-Password-Authentication",
    );