How write a right annotation/definition

[chemodun]

There is a game X4: Extensions with is use the Lua for some scenarios.
And it given a possibility to use Lua in modding.

And there is a question:
Engine is providing possibility to use some C functions.
In the Lua code from original game, it looks like:

local ffi = require("ffi")
local C = ffi.C
ffi.cdef[[
	void AddTradeWare(UniverseID containerid, const char* wareid);
]]

I tried to make an annotation file for it
like

C = {}

-- FFI Function: void AddTradeWare(UniverseID containerid, const char* wareid);
---@param containerid UniverseID
---@param wareid const char*
function C.AddTradeWare(containerid, wareid) end

But Language Server not shown this information in tooltip and stated it as unknown.
(field) C.AddTradeWare: unknown

Is there any possibility to make it work?

P.S. With other functions, "directly" accessible, i.e. without this
local ffi, local C everything is working fine

[chemodun]

Claude helps me. And on reddit I have a similar recommendation.
From Claude:
In annotation:

---@class C
C = {}

in code:

---@class C
local C = ffi.C

From reddit - thanks to IllustrisJack
in code

local C = {}
---@cast C C