Select the line, then type
C-u M-| jq -c sort C-u M-| jq -c sortIt feels great when you can use narrow-to-region² to perfect a complex address or write a custom function with all your editor's power at your fingertips. With the sad, but obvious, drawback that the changes aren't linked in your disjoint shell and editor history.
¹ https://manpages.debian.org/jessie/moreutils/vipe.1.en.html
² Nowadays, that is more likely https://github.com/chrisbra/NrrwRgn for me.