The provided code in the video does not seem to be working.
https://github.com/total-typescript/typescript-generics-workshop/blob/main/src/02-passing-type-arguments/11-data-fetcher.solution.ts
If you take the code and paste it into Typescript playground (I have done it for you) - you will get a bunch of errors.
The solution is as following:
const fetchData = async <T>(url: string): Promise<T> => await fetch(url).then(resp => resp.json as T)