Javascript flask tutorial

I am going through a tutorial, but it is not working and I can’t figure out why.

It is “Python + JavaScript – Full Stack App Tutorial”

https://www.youtube.com/watch?v=PppslXOR7TA

I downloaded the files whole sale, but when I use ‘npm run dev’ command it says

usage: vite [options]

A simple and minimal static site generator.

positional arguments:
{init,new,build,serve}
Options to help create, build and serve your project.

options:
-h, –help show this help message and exit
-v, –version show program’s version number and exit
PS C:Usersjudewdesktopusing python to interact with pdf and excel project!!! kevings program websiteold one for 1.5 hours can’t make workzzdowloadedfrontend>

When I try to go through the whole thing myself, it has a problem with line 70 is ContactList.jsx

{contacts.map((contact) => (

error is
Uncaught TypeError: Cannot read properties of undefined (reading ‘map’)

It looks like contact doesn’t exist, and it is empty because I am just starting the program, but I have no idea what the problem could be.