The code in the package is provides crypto implementations used by other packages.
npm install @iota/crypto.js
import { Converter } from "@iota/util.js";
import { Blake2b } from "@iota/crypto.js";
const sum = Blake2b.sum512(Converter.utf8ToBytes("abc"));
console.log(Converter.bytesToHex(sum));
The class and method documentation can be found in ./docs/api.md