In SB Episode 1 'Dungeons' are story exclusive. For the next episode (hopefully) they are planned to become accessible in free mode.
Viewing post in SlaveBar M ~ Episode 1 [v1.4] comments
Best place would be my website nymphokyun.net , additionally dlsite's circle ( https://www.dlsite.com/maniax/circle/profile/=/maker_id/RG64415.html ) and itch.io account ( https://itch.io/profile/nymphokyun )