I'm attempting to install a Kasa Smart 3 Way Switch (HS210). The installation instructions rely on the outlet box have two neutral (WHITE) wires being currently unused and wire-nutted together in the back of the outlet box.
When I took the plate off my the current switches (both of which control the same lights) this is what I found:
Box 1: There are two cables in this Box. One cable has a BLACK, WHITE and RED wire. The RED and WHITE wire go to the switch. The BLACK wire is under a wire nut with the WHITE wire from the second cable. The second cable has a WHITE and BLACK wire. The BLACK wire goes to the switch and the WHITE wire is under a wire nut with the BLACK wire from the first cable. [Going into the switch is a RED wire (top right), a WHITE wire (top left) a BLACK wire (bottom right) and a ground. In the back of the outlet box there was a BLACK wire and a WHITE wire, connected together by a wire nut.]
BOX 2: There is one cable in this box, with BLACK, WHITE and RED wires. [Going into the light switch is a WHITE wire (top right), a RED wire (top left) a BLACK wire (bottom right) and a ground. In the box, there is a no other wires.]
Coming off the KASA switch is a GREEN wire (labeled ground), a WHITE wire (labeled neutral) and than three screws: one labeled "load" and the other two labeled "travelers".
As mentioned, the instructions call for the outlet box having two WHITE wires connected together in the back box. Is there a way to safely install this if I don't have two WHITE wires, but do have a BLACK and WHITE wire connected together?
EDIT: Thank you for the replies. Edited to respond to the questions below. Here is a link to pictures of the boxes: https://drive.google.com/drive/folders/1OibESpeo_cEZXrPeIJdK1yjbl_s7ucUF?usp=sharing