How to enable TypeScript in an Angular template

When working with Angular, you may sometimes notice, that in a particular project, TypeScript is not supported in the template. It is not working. When you type a name of a property or method, your IDE should hint you with the proper name. Then all you have to do is to hit enter, to use the proper name.

Also, TypeScript should throw errors when you try to use properties or methods by wrong names.

Unfortunately, sometimes it does not work. How to fix it?