My friend had made an EOS contract and he has asked me to submit a random uint64, I need to generate this in nodejs.

Do I need to use a library like big number https://www.npmjs.com/package/big-number or or int64 https://github.com/broofa/node-int64 Ive read the docs and i just dont get it?

Do I then need to convert the number to hex before I send it to the contract?

Is there some library that will just give me a random uint64 ready to fire of to an EOS contract?