How to generate SSH public & private key in NodeJS using ssh2 library

const { utils: { generateKeyPair } } = require('ssh2');
const {writeFile} = require('fs/promises');

/**
 * ssh2's generateKeyPair as promise
 */
function SSHGenerateKeyPairPromise(keytype="ed25519", opts = {}) {
    return new Promise((resolve, reject) => {
        generateKeyPair(
            keytype, opts,
            (err, keys) => {
                if (err) { return reject(err) };
                return resolve(keys);
            }
        );
    });
}

/**
 * Run SSHGenerateKeyPairPromise() and save the keys to
 * opts.privateKeyPath and opts.publicKeyPath
 * @returns The generated keys
 */
async function SSHGenerateAndSaveKeyPairPromise(keytype="ed25519", opts = {}) {
    // Check if opts.privateKeyPath and opts.publicKeyPath are set
    if (!opts.privateKeyPath || !opts.publicKeyPath) {
        throw new Error("opts.privateKeyPath and opts.publicKeyPath must be set");
    }
    const keys = await SSHGenerateKeyPairPromise(keytype, opts);
    //Save keys to opts.privateKeyPath and opts.publicKeyPath using fs.promise
    await writeFile(opts.privateKeyPath, keys.private);
    await writeFile(opts.publicKeyPath, keys.public);
    return keys;
}

SSHGenerateAndSaveKeyPairPromise('ed25519', {
    privateKeyPath: 'id_ed25519',
    publicKeyPath: 'id_ed25519.pub'
}).then(keys => {
    console.log("Successfully generated ed25519 keys");
}).catch(err => {
    console.log(err);
});

SSHGenerateAndSaveKeyPairPromise('rsa', {
    bits: 8192,
    privateKeyPath: 'id_rsa',
    publicKeyPath: 'id_rsa.pub'
}).then(keys => {
    console.log("Successfully generated RSA keys");
}).catch(err => {
    console.log(err);
});