It is experimental, with a limited
[HotReload] C# subset. In the Editor, open the Window > Pipeline > Settings window, then in the Watcher section, click on Start. Note that you need to put the [HotReload] attribute on methods you intend to edit ahead of time and that it does not support all possible code changes - adding fields to a class is not supported etc.
source
https://discussions.unity.com/t/unity-pipeline-package-0-6-0-exp-1-is-available-now/1735626
#cli
