Module not found core import error NEXTJS 13

**Describe the bug**
Module not found even when providing unpkg url as corepath
Locally works without defining corepath but same does not work when deployed.
When providing anything as corepath it fails both locally and when deployed.

I have tried multiple versions of @ffmpeg and @ffmpeg/core, and they have the same issue.

ComingAlive has created this with nextjs https://github.com/comingAlive/ffmpegaudioextract.vercel.app

And it seems to work fine with defining the corepath. But he seems to be using nextjs 10 and an older version of webpack.
So I'm not too sure what the issue here is. Maybe something changed in nextjs 13 that's affecting this.

**To Reproduce**
Steps to reproduce the behavior:
Create next app
Create createFFmpeg
Define corepath

**Screenshots**
Logs from Vercel without corepath and with corepath.



**Desktop (please complete the following information):**
- Ubuntu 20.04