How to change position of legend

I have the following code producing a scatter plot and I would like to change the position of the legend so that is still outside the plot but in the center or middle, how could I do that?

 f <- list(
   family = "Courier New, monospace",
   size = 18,
   color = "#7f7f7f"
  )
 x <- list(
   title = "Age of Buildings",
   titlefont = f,
   zeroline = FALSE,
   showline = FALSE,
   showticklabels = TRUE,
   showgrid = TRUE
  )
  y <- list(
    title = "Total Violations",
    titlefont = f,
    zeroline = FALSE,
    showline = FALSE,
    showticklabels = TRUE,
    showgrid = TRUE
   )
fig2 <- plot_ly(final, x=~agebuilding, y=~violationstotal, mode= "markers", color = ~INdexrehabless6, size = ~totalvalue)
fig2 <- fig2 %>% layout(xaxis = x, yaxis = y, legend=list(title=list(text='<b> Housing Conditions </b>'))) #chaging name legend
fig2

Here is the plot I get

For the a legend with vertical orientation

• the default positioning corresponds to

  layout(legend = list(orientation = "v", y = 1, x = 1))

  and puts the legend in the top right corner of the plot.

• to put it at the bottom in the y-direction use

  layout(legend = list(orientation = "v", y = 0, x = 1))

• to have it centered in the y-direction use

  layout(legend = list(orientation = "v", y = .5, x = 1))

In case of a horizontal orientation

• the default positioning is

  layout(legend = list(orientation = "h", y = -.1, x = 0))

  and puts the legend in the lower left corner beneath the plot.

• to put it at the top in the y-direction use

  layout(legend = list(orientation = "v", y = 1.1, x = 0))