because the vscode use Fn keys(debug, rename, Go to...), and the karabiner is so heavy, so i do some work on Hammerspoon.

Fn_keys_for_app.lua

--- place the snippets in your ~/.hammerspoon/init.lua

local sys_key = {
    [3] = {pos = 1, key = 'F1'},  -- BRIGHTNESS_DOWN
    [2] = {pos = 2, key = 'F2'},  -- BRIGHTNESS_UP
    [22] = {pos = 5, key = 'F5'}, -- ILLUMINATION_DOWN
    [21] = {pos = 6, key = 'F6'}, -- ILLUMINATION_UP
    [20] = {pos = 7, key = 'F7'}, -- REWIND
    [16] = {pos = 8, key = 'F8'}, -- PLAY
    [14] = {pos = 9, key = 'F9'}, -- FAST
    [7] = {pos = 10, key = 'F10'}, -- MUTE
    [1] = {pos = 11, key = 'F11'}, -- SOUND_DOWN
    [0] = {pos = 12, key = 'F12'}, -- SOUND_UP
}

local app_fn = {
    ['Code'] = tonumber('010011111111', 2),  -- flag pos, active F1-F12 keys exclude F1,F3,F4
    --['xxx'] = tonumber('100000000000', 2),  -- flag pos, active only F1 key
}

local function tb_keys(tb)
    local t = {}
    for k in pairs(tb) do
        table.insert(t, k)
    end
    return t
end

hs.eventtap.new({hs.eventtap.event.types.systemDefined}, function(event)
    local keyobj = event:systemKey()
    local keycode = keyobj.keyCode
    -- capture the system code print(hs.inspect.inspect(keyobj))
    if not keycode then return false end
    local current_app = hs.application.frontmostApplication()
    for name, mask in pairs(app_fn) do
        if name == current_app:name() then
            local t = sys_key[keycode]
            if t then
                if 1 << (12 - t.pos) & mask == 0 then return false end
                local key_event = hs.eventtap.event.newKeyEvent(tb_keys(event:getFlags()), t.key, keyobj.down)
                key_event:post(current_app)
                return true
            end
        end
    end
end):start()