Installing kasa 3-way switch

[Helloyellow]

Hi everyone. I bought one of those smart switches, specifically the Kasa 3 way kit (HS210 KIT).

But when I opened my 3 way dumb switches I see only those wires:

Downstairs switch:
One wire: black, red, white coming out. Those are connected to the switch.

Upstairs switch
Two wires:
One wire: black, red, white all connected to switch.
Second wire: black and white only. These two are marrette together and tucked into the back.

Looking at this, I don't believe there's a neutral? Unless that black wire marralette with the white is actually a neutral?

I tried googling various wiring diagrams and I have no clue how the wiring works.

Thanks!