title: Dash.plotly dosn't show cohort graph to me
body: <p>my code in colab
  <a href="https://colab.research.google.com/drive/1pjbp2EpbjNPzEOP7c9mcjYVqoclOsI7r#scrollTo=qhDz0qWoGUA-" rel="nofollow noreferrer">https://colab.research.google.com/drive/1pjbp2EpbjNPzEOP7c9mcjYVqoclOsI7r#scrollTo=qhDz0qWoGUA-</a></p>
  <p>dataset
  <a href="https://www.kaggle.com/carrie1/ecommerce-data" rel="nofollow noreferrer">https://www.kaggle.com/carrie1/ecommerce-data</a></p>
  <p>the problem is figure dosn't show and cohort graph dosn't show percentage as per referenced example
  1- I want to fix percentage as per referenced example
  2- I want to show the graph in the dashboard</p>