How to rename output channels of sub shader graph?

Hi, sub shader graph is cool but does anyone know how to rename those output channels? I can't find such an option and it's confusing to use names like output1, output2, etc.

 

You can click the output node in the subgraph, click on the names you wanna change (like Out_Vector1), and type your new name. Unity doesn't do the blinking cursor interface for changeable text like they do for renaming everything else. I got confused too.

https://docs.unity3d.com/Packages/com.unity.shadergraph@6.9/manual/Custom-Port-Menu.html