The nazi party used a lot of euphemism surrounding their genocide plan and a lot of german citizens claimed afterwards they didn’t know the extent of it (davon haben wir nichts gewusst), but the antisemitism was immediately visible obviously what with the kidnapping. The camps—a bit less so, but a lot of historians feel they were more of an open secret than a secret. It was definitely less globally visible than what’s happening in Palestine though and the international community was justifiably outraged when they saw the extent and brutality of the camps.