That is "duplicate line down" -- I want "duplicate line up" which copies the current line to the line above the cursor. My open request been sitting in jetbrains "ignore it" for many many years.
You can achieve anything with macros and you can give shortcuts to a named macros.
Macros are in the Edit > Macros menu. Add a shortcut to a macro in Settings , Keymap > search Macros, right click on Play Saved Macro and Add Keyboard Shortcut.