The content requirements are fairly easy for the first 10 chapters; no matter what your operating system or your code editor is, you're always covered.
However, in Chapter 11, Integrating Firebase with Android/iOS Natively, we'll start developing for mobile, so while you will be perfectly fine with any operating system (macOs, Linux, or Windows) when developing for Android, we will definitely need a macOS-based computer in order to follow along with iOS-based recipes.