I am curious if this companies hiring requirement would be a red flag for you. They want at least one year of Typescript experience. Fine. They would not consider a person with 5 years of Javascript and zero Typescript experience.

Thats says something about thier internal communications.
Avoid.

Typescript is not JavaScript.

It makes sense.

A full year of hands on experience with TS is an entirely different thing then a year of experience with JS.

That actually is a good sign. they want to make sure, that you don't use the any type everywhere (extra points for knowing when to use the unknown type).

Yeah take a tutorial and don't say you have "zero" experience.
TS actually needs a rewrite of some JS neurons. Talking as someone who had to use it for a University project after 4 years of vanilla JS experience.

Green flag for me.
The longer you work on JS, the harder it’ll be for you to switch over to TS.
JS devs who switch over to TS usually perceive the latter as a language working against them, because yeah you’re gonna be running into a shitload of errors quickly and you’ll be banging you’re head trying to figure them out, ultimately feeling like you’re not getting anything done.

It can take a while before you start understanding the many benefits of strong static typing.
Company mentioned in OP probably doesn’t want to deal with frustrated JS devs learning TS

TypeScript been for 10 years already and kept JS world from ruining entirely, to the point that it indefinitely craves for it. No idea how "JS-purists" would get anything decent now, to be frank.

correct, actually.
since typescript's main point is to disable JavaScript's type looseness, JavaScript devs tend to get annoyed by it very quickly and they start circumventing it by using "any" everywhere.

talking from experience of being that guy as well as working with a code of another that guy.