R Plotly add image watermark

Question

I would like to have an image/watermark added to a double y-axis plot, somehow my code doesnt work..... How is this possible? It doesnt error but the image is not added

df <- data.frame(x = 1:50,
                 y1 = c(20:5,6:10,9:3,4:20, 19:15),
                 y2 = c(100:115,200:204,50:44,4:20, 66:62))

And my code

plot_ly(df) %>% 
  add_lines(type = 'scatter', mode = "lines", 
            name = "test", 
            x = ~x, y = ~y1,
            line = list(color = '#999999'),
            hoverinfo = "text",
            text = ~paste(round(y1, 1), x))  %>%
  add_lines(type = 'scatter', mode = "lines", 
            name = "test", yaxis = 'y2',
            x = ~x, y = ~y2,
            line = list(color = '#CC79A7'),
            hoverinfo = "text",
            text = ~paste(round(y2, 1), x)) %>%
  #layout
  layout(title = "test",
         xaxis = list(titel = "Date", 
                      rangeslider = list(thickness = 0.05)),
         yaxis = list(side = 'left', title = 'test', 
                      showgrid = F, zeroline = F, type = "log",
                      showline = T),
         images = list(source = "https://rstudio.com/wp-content/uploads/2018/10/RStudio-Logo.png",
                       xref = "paper",
                       yref = "paper",
                       xanchor = "left", 
                       yanchor = "bottom",
                       x= 4,
                       y=4,
                       sizex = 5,
                       sizey = 5,
                       opacity = 0.8),
         yaxis2 = list(side = 'right', overlaying = "y", 
                       title = 'test', 
                       showgrid = F, zeroline = F, 
                       showline = T))

Answer 1

The problem is that you have no access to the Rstduio-logo.png.

1. Create a www folder
2. Put a.png in this www folder let's say I call it test.png
3. Then simply:

layout(images = list(source = "test.png"))