an example of create an pixel event using elixir

ex_pixel.ex

defmodule Fb.Pixel do
  @moduledoc """
  Facebook Pixel
  requires HTTPPoison, Jason
  """

  @pixel_id Application.get_env(:fb, :pixel_id)
  @api_version Application.get_env(:fb, :fb_graph_api_version)

  def create_events(token, events, test_event \\ nil) do
    test_event = case test_event do
      nil -> []
      event -> [test_event_code: event]
    end

    params =
      [
        params: [
          data: Jason.encode!(events),
          access_token: access_token,
        ] ++ test_event
      ]

    HTTPoison.post(
      "https://graph.facebook.com/#{@api_version}/#{@pixel_id}/events",
      "",
      [],
      params
    )
  end
end

# example usage, please notice is our :fb Application OTP, so you should put in your own :my_app or whatever.

# config: :fb,
#   pixel_id: "pixel_id_get_from_fb"
#   pixel_access_token: "get_from_fb"
#   fb_graph_api_version: "v7.0"

# email_hash = :sha256 |> :crypto.hash("dev@paridin.com") |> Base.encode16(case: :lower)
# events = [
#   %{
#     "event_name" => "Purchase",
#     "event_time" => 1_592_937_775,
#     "user_data" => %{
#       "em" => email_hash,
#       "ph" => nil
#     },
#     "custom_data" => %{
#       "currency" => "USD",
#       "value" => "142.52"
#     }
#   }
# ]

# events = [
#   %{
#     "event_name" => "InitiateCheckout",
#     "event_time" => 1_592_937_779,
#     "user_data" => %{
#       "client_ip_address" => "10.10.1.1",
#       "client_user_agent" => "Firefox"
#     },
#     "custom_data" => %{
#       "visiting" => "MEXICO",
#       "session_id" => "435sdvsdfXd2"
#     }
#   }
# ]

# token = Application.get_env(:fb, :pixel_access_token)
# Fb.Pixel.create_event(token, events)

# Fb.Pixel.create_event(token, events, "TEST001")