how can use throw new error to send a error response in postman

I am using firebase cloud functions and I want to validate my api request call on postman. On wrong input it must send a error response back to my postman.

api call

const validator = require('./libs/validators');
export const createUser = functions.https.onRequest((req, res) => {
  // @ts-ignore
  // ts-lint:disable-next-line
  corsHandler(req, res, async () => {
    const validData = validateData(req.body);
    res.send(validData);
    try {
      const user = await admin.auth().createUser({ email: validData.email, password: validData.password });
      await admin.auth().setCustomUserClaims(user.uid, { isAdmin: false, isSubscribed: false });
      await admin.firestore().collection('users').doc(user.uid).set(
        { validData }, { merge: true }
      );
      res.send(user);
    } catch (e: any) {
      throw (res.status(400).send(e.message));
    }
  });
});

function validateData(body: any) {
  if (body === undefined) {
    throw Error("Invalid data");
  }
  return validator.newStudentValidator(body);
}

validators.ts

export const newStudentValidator = function (body: any) {
    try {
        if (body.name === null) {
            throw new Error('name is required');
        }
        if (!body.email.match(/^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/)) {
            throw new Error("Invalid email");
        }
        if (body.password === undefined) {
            throw new Error("Password is undefined");
        }
        if (body.university === undefined) {
            throw new Error("University is undefined");
        }
        if (body.sem === undefined) {
            throw new Error("Semister is undefined");
        }
    }
    catch (e: any) {
        throw new Error(e.message);
    }
    const allowed = ['name', 'email', 'password', 'university', 'sem'];
    const filtered = Object.keys(body).filter(key => allowed.includes(key)).reduce((obj: any, key) => {
        obj[key] = body[key];
        return obj;
    }, {});
    return filtered;

}

i get this error everytime enter image description here