How to add several segment to 3D plot

I tried to connect several points in 3D plot. But it produced errors. Can you help me to add lines to some points rather than all points? Many thanks.

“Error: Columns x, y must be length 1 or 61321, not 3, 3”

plot_ly(dc, x=~x, y=~y, z=~z, mode=“markers”,
color = day,
marker = list(size =5,opacity=1)) %>%
add_trace(x =c(0,0,0) , y= c(1,1,0) , mode = “lines”)