Can't create a TypeScript file (.ts) in IntelliJ on Mac!

Hello guys,

I'm using IntelliJ to make a new project for my subject. However, my IntelliJ can't read TypeScript file (but other programs can) I also can't create a new TypeScript file (.ts) although I installed NodeJS and npm, it said: "The file abc.ts is not associated with any file type" so I really need your helps. Thank you for helping me!!!