When a non-Apple device is said to be Airplay compatible, that almost always always means as a receiver as transmission seems restricted to a very small number of devices viz. “all iPhone, iPod touch, iPad, and Mac models from late 2012 or after running the latest version of their operating system. In addition, you can also use AirPlay on iTunes for Windows, but that’s the extent of its Windows support. All these are essentially sender devices, meaning they can initiate a stream or mirror from them to a receiver device.“ There may be some exceptions to that I.e. some third party companies who have licensed the ability to transmit airplay, but none come to mind.
See the “Which devices support Airplay?” section in this link:
https://www.xda-developers.com/airplay/
For example, I have a Linn MDSM/4 which also supports Airplay 2, but I wouldn’t expect it to send a stream to another airplay device.