How to move over CORS from router to endpoint

So I have a very simple signup/login website, signup works very well but when it comes to login, it does not do anything, people already suggested my to use corsica but I have no clue how to move that over. this is how my router.ex looks like

defmodule TestWeb.Router do
  use TestWeb, :router

  pipeline :api do
    plug TestWeb.Plugs.RateLimiter
    plug :accepts, ["json"]
    plug TestWeb.Plugs.AuthPlug

  scope "/", TestWeb do
    pipe_through :api

    post "/login", UserController, :login
    post "/signup", UserController, :signup
    get "/test", UserController, :test

    # The old CORS stuff that I have to move over to endpoint.ex
    options "/login", UserController, :login
    options "/signup", UserController, :signup
    options "/test", UserController, :test

My endpoint.ex currently looks like this

plug Corsica, origins: "*"

but what else do I have to add to the endpoint and remove from the router? because in the endpoint file I cant use pipeline (like in the router) as its a unknown function. Its the first time for me attempting to fix CORS issues in general + very new to phoenix. Yes, I already looked at the docs but I only was able to move over that one line and I feel like I am still missing something