Sure here is the relevant part of the code:
import express from 'express';
import { RelayPool } from 'nostr';
import converter from 'bech32-converting';
import WebSocket from 'ws';
import fs from 'fs';
import cors from 'cors';
import { getSignature, validateEvent, verifySignature, getEventHash, getPublicKey, nip04 } from 'nostr-tools';
let sk1 = 'LONG_STRING_IN_HEX_FORMAT'
let pk1 = 'LONG_STRING_IN_HEX_FORMAT'
let pk2 = 'LONG_STRING_IN_HEX_FORMAT'
pool.on('open', relay => {
let event = {
kind: 4,
pubkey: pk1,
created_at: Math.floor(Date.now() / 1000),
tags: [['p', pk2]],
content: 'hello world',
};
event.id = getEventHash(event);
let signedEvent = signEvent(event)
event.sig = getSignature(event, sk1);
let ok = validateEvent(event)
let veryOk = verifySignature(event)
});