Where to store some important data fetched from API so that I can use it in multiple routes?

const express = require("express"); const router = require("express").Router(); const rp = require("request-response"); router.post("/sendOTP", (req, res) => { const { mobile_number } = req.body; // receive the mobile number const otp = randomize("0000"); // generated 4 digit otp options = { method: "GET", url: "xxxxx/xxxxx/xxxxx/${otp}", // calling my otp service provider to send otp to my user } rp(options).then((response)=>{ // response.details contains the unique otp session id which I have to use in another route where I am verifying otp }).catch((err) => console.log(err)); }); router.post("/getOTP", (req, res) => { // user will put otp he received from his mobile const { otp } = req.body; // receive the otp options = { method: "GET", url: "xxxxx/xxxxx/xxxxx/${otp}/${otp_session_id}", // calling my otp service provider with otp and session id of otp } rp(options).then((response)=>{ console.log(response) // otp verified. }).catch((err) => console.log(err)); });