reset request queue in node.js vanilla server - node.js

Question

I have a program that accepts POST requests with a body that contains numbers. My program checks is the numbers in body are prime numbers or not. Everything is well the first time, but every time after that the program remembers the past POST requests a checks them as well.
how can I reset the request queue so my program will only check the newest POST request?
here is the code:
import { createServer } from "http";
import { parse } from "querystring";
import { url } from "inspector";
import { port } from "./config.js";
let body = "";
let checkNumber = true;
const PORT = process.env.PORT || port;
const server = createServer(async (req, res) => {
res.statusCode = 200;
res.setHeader("Content-Type", "text/html");
const FORM_URLENCODED = "application/x-www-form-urlencoded";
const POST_PATH = "api/numbers/prime/validate";
const GET_PATH = "api/numbers/prime";
if (req.headers["content-type"] === FORM_URLENCODED) {
//console.log(req.method);
if (req.method === "POST") {
req.on("data", (chunk) => {
body += chunk.toString();
});
}
if (req.url === `/${POST_PATH}`) {
let re = parse(body);
await checkValuesInObject(re);
console.log(checkNumber);
res.end(`${checkNumber}`);
}
res.end();
});
server.listen(PORT, () => {
console.log(`listening on port ${PORT}`);
});
async function checkIfFirstNumber(number) {
if (number == 1) {
return false;
} else {
for (let i = 2; i < number - 1; i++) {
if (number % i === 0) {
return false;
}
}
return true;
}
}
async function checkValuesInObject(obj) {
const amount = Object.keys(obj);
for (let i = 0; i < amount.length; i++) {
let valueAmount = obj[Object.keys(obj)[i]];
for (let j = 0; j < valueAmount.length; j++) {
checkIfFirstNumber(valueAmount[j]).then((answer) => {
console.log(`answer: ${answer}`);
if (!answer) {
checkNumber = false;
}
});
}
}
checkNumber = true;
}
async function printPrime(number) {
let numbers = "";
for (let i = 2; i <= number; i++) {
const check = await checkIfFirstNumber(i);
if (check) {
numbers += i + " ";
}
}
return numbers;
}