If you are looking for the software , it is not free . It requires a purchase after the trial period. If you need a truly free alternative for screen mirroring, LetsView is currently the most reliable free option available.
AirMyPC is not free software; it is a paid commercial product. However, the developers do offer a fully functional . airmypc free
If you later want macro support, multi-touch customization, or no ads, the Pro version is a one-time $4.99 (no subscription). But try the free version first. Chances are, it’s enough. If you are looking for the software , it is not free