lucasf hi,
sorry for the late reply, I've missed it.
To use this you must have an auth system to "send" your users to Flarum. If I understand correctly, your AWS pool is different from the one you use with WordPress, so you can't use WP as your auth system.
You can write a small PHP app that acts as auth system for your users and then use the PHP plugin to redirect them to Flarum, although the best solution would be a custom Flarum extension that interacts with your AWS PHP SDK and imports/manages users and the authentication
