Getting error when calling sendVerificationCode.

Tech Stack Used : Nodejs:

    async (req, res, next) => {
  // #swagger.tags = ['Auth']
// #swagger.description = ' This endpoint allows to create a post'
const { phoneNumber, recaptchaToken } = req.body;
  console.log(recaptchaToken);
const identityToolkit = google.identitytoolkit({
  auth: process.env.GCP_API_KEY,
  version: 'v3',
});


const response = await identityToolkit.relyingparty.sendVerificationCode({
  phoneNumber,
  recaptchaToken,
});

// save sessionInfo into db. You will need this to verify the SMS code
req.user.sessionInfo=response.data.sessionInfo;
await req.user.save();
res.status(200).json({success:true,data:"Otp sent"});
}

How to resolve this? I have tried every way I know.