ModuleScript Assets unable to require?

Hello, When i was working with Modules lately, I attempted to upload the ModuleScript to the ROBLOX Site, therefore allowing the usage of private modules. However when i renamed the ModuleScript to 'MainModule' and updated it to the site as a model, as i tried to require the module using its assetid. My original code isn't as simple as this, but it still failed to work like the following.

Here is a code example of the situation:

Inside the ModuleScript

local test = {}

function test:add(x, y)
    return x + y
end

return test

Inside the Script

local library = require(378772246) -- This is the assetId of the module
print(library:add(1,2)) -- It didn't print anything or error in the output

Edit: I have placed the script in ServerScriptService.when the module is placed in-game and required, the function fired, but not from an asset.