Next.jsアプリをHostingしたらGoogleTTSから音声出力されない

import * as functions from 'firebase-functions';
import { googleTts } from '../../src/features/googletts/googletts';
import express from 'express';
import cors from 'cors';

const app = express();

// CORS設定を追加
app.use(cors({ origin: true }));

app.get('/googleTtsFunction', async (req, res) => {
  const message = req.query.message as string || 'Hello, world!';
  const ttsType = req.query.ttsType as string || 'en-US-Standard-F';
  console.log(req.query);
  try {
    const { audio } = await googleTts(message, ttsType);
    res.setHeader('Content-Type', 'audio/wav');
    res.send(audio);
  } catch (err) {
    console.error('ERROR:', err);
    res.status(500).send(err);
  }
});

exports.googleTtsFunction = functions.https.onRequest(app);

export async function googleTts(
  message: string,
  ttsType: string
) {
  try {
  // Imports the Google Cloud client library
  const textToSpeech = require('@google-cloud/text-to-speech');
  // Creates a client
  const client = new textToSpeech.TextToSpeechClient();

  // Construct the request
  const request = {
    input: {text: message},
    // Select the language and SSML voice gender (optional)
    voice: {languageCode: 'en-US', name: ttsType, ssmlGender: 'FEMALE'},
    // select the type of audio encoding
    audioConfig: {audioEncoding: 'LINEAR16'},
  };

  // Performs the text-to-speech request
  const [response] = await client.synthesizeSpeech(request);

  return { audio: response.audioContent };
  } catch (error) {
    console.error('Error during TTS request:', error);
    throw new Error('TTS request failed');
  }
}

useEffect(() => {
    const storedChatVRMParams = window.localStorage.getItem("chatVRMParams");
    if (storedChatVRMParams) {
      const params = JSON.parse(storedChatVRMParams);
      const updatedParams = {
        ...params,
        gsviTtsServerUrl: process.env.NEXT_PUBLIC_TTS_URL || "http://127.0.0.1:5000/tts",
      };
      window.localStorage.setItem("chatVRMParams", JSON.stringify(updatedParams));
      setGSVITTSServerUrl(updatedParams.gsviTtsServerUrl);
    }
  }, [process.env.NEXT_PUBLIC_TTS_URL]);

  /**
   * 音声を再生し、リップシンクを行う
   */
  public async speak(buffer: ArrayBuffer, screenplay: Screenplay) {
    this.emoteController?.playEmotion(screenplay.expression);
    await new Promise((resolve) => {
      this._lipSync?.playFromArrayBuffer(buffer, () => {
        resolve(true);
      });
    });
  }

  public playEmotion(preset: VRMExpressionPresetName) {
    if (this._currentEmotion != "neutral") {
      this._expressionManager?.setValue(this._currentEmotion, 0);
    }

    if (preset == "neutral") {
      this._autoBlink?.setEnable(true);
      this._currentEmotion = preset;
      return;
    }

    const t = this._autoBlink?.setEnable(false) || 0;
    this._currentEmotion = preset;

    // 目を開ける
    this._expressionManager?.setValue(VRMExpressionPresetName.Blink, 0);

    // 表情をセット
    this._expressionManager?.setValue(preset, 1);

    // 表情保持時間を取得し、保持後に neutral に戻す
    const delayTime = this.getDelayTime(preset) * 1000;
    setTimeout(() => {
      this._expressionManager?.setValue(preset, 0);
      this._expressionManager?.setValue("neutral", 1);
      this._currentEmotion = "neutral";
    }, delayTime);
  }

  public lipSync(preset: VRMExpressionPresetName, value: number) {
    if (this._currentLipSync) {
      this._expressionManager?.setValue(this._currentLipSync.preset, 0);
    }
    this._currentLipSync = {
      preset,
      value,
    };
  }

  public update(delta: number) {
    if (this._autoBlink) {
      this._autoBlink.update(delta);
    }

    if (this._currentLipSync) {
      const weight =
        this._currentEmotion === "neutral"
          ? this._currentLipSync.value * 0.5
          : this._currentLipSync.value * 0.25;
      this._expressionManager?.setValue(this._currentLipSync.preset, weight);
    }
  }