Check out A simple way to feed ADS-B data - can feed one or many destinations, installation is guided and complexity ranges from easy to advanced (you choose, end result is same feeding). In my experience, I recommend something a bit more robust than a Rasperry Pi 3B+ (e.g a Pi4 or 5, a thin client or similar) if using other than an ADS-B dongle (e.g. AirSpy) or feeding more than a couple of sites.
If you go for do-it-yourself, there are many guides/experiences in this forum by @abcd567 @wiedehopf @caius @foxhunter and many others.