how to use react native mobile app with raspberry pi

I want to build an app in react native that receives sensor data from Raspberry Pi 3B, displays it, and stores it in a Firebase backend. I can't find much information online about how I could do this. Do I receive the information from the RPi using Python and then transmit it to the app, or do I use JavaScript to collect the data? If the former, how do I use Python with react native, and if the latter, what Raspberry Pi library can I use with JavaScript?