title: interactive plot_ly() in R is empty
body: <pre><code>df &lt;- data.frame(PC1=c(0.05,0.056,0.0256),PC2=c(1.025,0.256,-2.548),PC3=c(3.35,-2.458,-3.66))
  fig &lt;- plot_ly(df,type = 'scatter',mode = 'markers') 
  fig
  </code></pre>
  <p><code>fig</code> is empty. Why? I have already looked into here <a href="https://plotly.com/" rel="nofollow noreferrer">https://plotly.com/</a> .</p>