I am using the following starter kit: https://vercel.com/templates/next.js/nextjs-fastapi-starter

If I try and test the FastApi backend locally it works great, however if I deploy the project on vercel I get the following error whenever I try and call the function:
Vercel error log

I tried visiting the link that was provided in the error message, but didn’t find anything useful.

Does anyone have any advice to solve this issue? I feel like this should be an easy deployment as it is one of the provided templates that vercel shows on their website.