A code block folding feature Follow

I love Webstorm much. I just saw a nice feature in the menu "Code -> Folding -> Fold Code Block". Though I don't know what is the purpose of it, i.e. when and how to use this feature. Whenever I have some blocks of code "Fold Code Block" always is grayed out. I clicked here and there but this one always disabled. I see it is redundant feature, or am I missing something? Otherwise could you be pleased provide some example when it is useful? Thanks. Webstorm ver. 2022.1.3