VSCode & Prettier not working

I am trying to get prettier running in VSCode but it simply does not work. The problem is that I am using a TypeScript Monorepo which looks like this:

|--- api
    |--- package.json
    |--- tsconfig.json 
    |--- server.ts
|--- www
    |--- pages
         |--- index.tsx
    |--- package.json
    |--- tsconfig.json
|--- now.json
|--- package.json

My VSCode settings for prettier are set to default. The curious thing about the whole scenario is that in the folder www prettier is working as usual. But as soon I open api/server.ts prettier doesnt do anything.

Does somebody have a solution for this?