How to use the home-assistant-js-websocket.getAuth function in home-assistant-js-websocket

// We don't load the component when onboarding is done
        document.location.assign("/");
        return;
      }

      const steps: OnboardingStep[] = await response.json();

      if (steps.every((step) => step.done)) {
        // Onboarding is done!
        document.location.assign("/");
        return;
      }

      if (steps[0].done) {
        // First step is already done, so we need to get auth somewhere else.
        const auth = await getAuth({
          hassUrl,
        });
        history.replaceState(null, "", location.pathname);
        await this._connectHass(auth);
      }

      this._steps = steps;
    } catch (err) {
      alert("Something went wrong loading onboarding, try refreshing");
    }
  }

private async _handleStepDone(
    ev: HASSDomEvent>
  ) {
    const stepResult = ev.detail;
    this._steps = this._steps!.map((step) =>
      step.step === stepResult.type ? { ...step, done: true } : step
    );

    if (stepResult.type === "user") {
      const result = stepResult.result as OnboardingResponses["user"];
      this._loading = true;
      try {
        const auth = await getAuth({
          hassUrl,
          authCode: result.auth_code,
        });
        await this._connectHass(auth);
      } catch (err) {
        alert("Ah snap, something went wrong!");
        location.reload();
      } finally {
        this._loading = false;
      }
    } else if (stepResult.type === "core_config") {
      // We do nothing
    } else if (stepResult.type === "integration") {
      const result = stepResult.result as OnboardingResponses["integration"];
      this._loading = true;

private async _handleConnectMessage(msg: ConnectMessage) {
    let auth;
    try {
      auth = await getAuth({
        loadTokens: async () => ({
          hassUrl: msg.hassUrl,
          clientId: msg.clientId,
          refresh_token: msg.refreshToken,
          access_token: "",
          expires: 0,
          expires_in: 0,
        }),
      });
    } catch (err) {
      this._error = this._getErrorMessage(err);
      return;
    }
    let connection;
    try {
      connection = await createConnection({ auth });