How to implement Diffie-Hellman algorithm in JS (antiderivative modulo)?

Question

JavaScript

Hello. Actually, there was a need to exchange keys without the participation of the server. To do this, you need to implement the DH algorithm in js. Googling has not been successful.
More precisely, the problem arose when searching for the antiderivative modulo. Are there ready-made functions so as not to write a bicycle?
PS: if you tell me a lib for DH on js, I will be very grateful.

Answer 1

First thing I googled: https://github.com/crypto-browserify/diffie-hellman