500 Due to require statement failing

500 Due to require statement failing

Thank you for the response! Yes, both are in the package.json within the dependencies. When running `vercel dev` it works great. But when i try to run in vercel in a preview, it has this error.

500 Due to require statement failing

I am trying to publish an Express JS API to Vercel (server, not serverless). I was able to follow some tutorials on getting it published. However, when running locally it works...