How can I bind a shortcut to trigger an custom function aginst the element under cursor?

[LintaoAmons]

I want to have a short cut to open the buffer element under cursor in a popup window.
So wondering how could I do it~
I saw there are actions can be trigger by shortcuts, but besides those predefined actions, how can I trigger a customised function with the context of selected item.

[ibhagwan]

how can I trigger a customised function with the context of selected item.

You’d have to write a custom action with code that uses the contents of the selected item , it’s up to you how to get it, if it’s an existing buffer you can use vim.api.nvim_buf_get_lines, otherwise you can read the file using libuv (vim.uv) or readfile(), :FzfLua helptags is your friend.