Postman accesss token & refresh token get automation script

postman-script.js

const url = `${pm.environment.get("base_url")}/signin`;
const email = pm.environment.get("email");
const password = pm.environment.get("password");

const postRequest = {
  url: url,
  method: "POST",
  header: "Content-Type:application/json",
  body: {
    mode: "application/json",
    raw: JSON.stringify({
      email: email,
      password: password,
    }),
  },
};

let getToken = true;
const accessToken = pm.environment.get("access_token");
const idToken = pm.environment.get("identity_token");
const expiresIn = pm.environment.get("expires_in");

if (accessToken && idToken && expiresIn) {
  if (expiresIn >= new Date().getTime()) {
    getToken = false;
  }
}

if (getToken) {
  pm.sendRequest(postRequest, (err, res) => {
    if (!err) {
      var responseJson = res.json();
      pm.environment.set(
        "access_token",
        responseJson.data.access_token
      );
      pm.environment.set("identity_token", responseJson.data.id_token);

      let expiryDate = new Date();
      expiryDate.setSeconds(
        expiryDate.getSeconds() + responseJson.data.expires_in
      );
      pm.environment.set("expires_in", expiryDate.getTime());
    }
  });
}

Variables required on postman collection

base_url
email
password
access_token
identity_token
expires_in