Alright, solved generating monero wallets problem like that (using Meteor.js):
Downloaded this AWESOME repo: https://github.com/mymonero/mymonero-core-js
Unpacked this repo to the node_modules folder.
On client startup entered this code:
const walletUtils = require('mymonero-core-js/monero_utils/monero_wallet_utils')
const wallet = walletUtils.NewlyCreatedWallet('english', 0)
console.log('## Wallet address:', wallet.keys.public_addr)
console.log('## Mnemonic seed:', wallet.mnemonicString)
So I connected mymonero-core-js lib, and used their function " NewlyCreatedWallet " to create new wallet + mnemonic phrase ( second parametr is network, where 0 is mainNet, 1 is testNet and 2 is STAGENET ).
Everything is working, now I can generate monero wallets !