How to mapping 's' with two different behavior

[vurtune]

I have this to map 's' to do leap forward to, and if I press n followed by 's' it supress n character. There is two different behavior because I use 's' to continuously supress characters before enter in insert mode.
I don't use Leap jump characters.

vim.keymap.set({ "n", "x" }, "s", "v:count == 0 ? '<Plug>(leap-forward-to)' : 's'", { expr = true })

But it doesn't work even if I put "remap = true".
What I'm doing wrong?

[vurtune]

vim.keymap.set({ "n", "x" }, "s", function () if vim.v.count == 0 then require("leap").leap {} else vim.api.nvim_feedkeys(vim.v.count .. "s", "n", false) end end, { desc = "Leap forward" })