example of Config ?

Dear Erlangers,

Reading from the application module;

https://erlang.org/doc/man/application.html

set_env(Config) -> ok
    
set_env(Config, Opts) -> ok
    
Types
Config = [{Application, Env}]
Application = atom()
Env = [{Par :: atom(), Val :: term()}] ...

From a wx:demo() example;

https://github.com/erlang/otp/blob/master/lib/wx/examples/demo/ex_notebook.erl

-module(ex_notebook).

-include_lib("wx/include/wx.hrl")

-behaviour(wx_object).

-export([start/1, init/1, terminate/2,  code_change/3,
     handle_info/2, handle_call/3, handle_cast/2, handle_event/2]).

-record(state, 
    {
      parent,
      config,
      notebook
     }).

start(Config) ->
    wx_object:start_link(?MODULE, Config, []).

%%
init(Config) ->
        wx:batch(fun() -> do_init(Config) end).
do_init(Config) ->
    Parent = proplists:get_value(parent, Config),  ...

Between the application module and the wx example above, I doubt this
would be the same Config.

Could someone kindly post a URL to an example of what Config might be
for wx_object?

Thank you in advance,
Peter