AuthenticatorActivity.kt

// Configure the Auth0 requirements
val auth0Settings = Auth0(this).apply {
    isOIDCConformant = true
}
val audience = String.format("https://%s/userinfo", resources.getString(R.string.com_auth0_domain))
loginFormAuth0LoginButton.onClick {
    WebAuthProvider.init(auth0Settings)
        .withAudience(audience)
        .start(this@AuthenticatorActivity, object : AuthCallback {
            override fun onSuccess(credentials: Credentials) {
                runOnUiThread { toast("Auth0 Authenticated Successfully") }
                Log.d(TAG, "ID Token = ${credentials.idToken}")
            }
            override fun onFailure(dialog: Dialog) {
                Log.d(TAG, "Auth0 Error displayed in dialog")
                runOnUiThread { dialog.show() }
            }
            override fun onFailure(exception: AuthenticationException?) {
                runOnUiThread { toast("Auth0 Authentication Failed") }
                Log.e(TAG, "Auth0 Error: ${exception?.localizedMessage}")
            }
        })
}