Apple today released tvOS 15.5 Beta to developers, the specific version number is (19L5547e), the software was launched three weeks after the release of tvOS 15.4.
Developers can download the new tvOS 15.5 betas by using Xcode to download a configuration file to the Apple TV. Updates to tvOS are usually small in scale and focus on bug fixes and improvements rather than breaking externally facing changes.
Apple previously released the official version of tvOS 15.4, the current stable version of tvOS, adding support for dedicated WiFi networks, allowing an iPhone or iPad to connect an Apple TV to networks that require additional sign-in steps, such as hotel rooms and college campuses.