This no longer works.

[DiamondRoPlayz]

When you try use it, it will just keep erroring.

[meiraxx]

What is the function you're using? You're probably using deflate.

The deflateSync function doesn't require you to specify a second argument.

If you absolutely need deflate, simply specify the callback argument: deflate(data, function(){doSomethingHere}).
If you do this, the "undefined" error will no longer occur since you now specified the "callback" function argument.

Furthermore, run npm install zlib, rather than using node:zlib, which is deprecated.

Hope that helps 👍