you have to talk to the mystery woman on the nexus, if it shows up as "???" then you probably haven't met her yet, tbh i don't know what i did to meet her.
I saw someone talking about the nexus but I don't know how to use it
when u press the bed usually to sleep, there is an option to go to the nexus if u already unlock it
what i did was sleep before nighttime, but i'm not 100% sure that's what unlocks it. still, it's worth a shot
