Does anyone know how this is done?

The easiest way is to use toybox.

Yeah, probably,not a fan of Toybox though. Having them linked to my account would be better, but the provided links don't do anything. Owlcat page links to Twitch page, Twitch page links back to Owlcat page, neither allows me to connect accounts between them.

Why the hell would they introduce a feature that isn't friendly to use? It should just be a link with login and done.

You have to link accounts and watch the right streams for one hour ... or use toybox for 1 minute. Such ad-rewards practices are shameful.