Bar chart test 13 & 14

I am almost done with my bar chart…but I can’t seem to pass the last two tests. I am trying to add a basic tooltip using .append('title) but can’t seem to get it to work

here is my code that I am trying to get to work

  .on('mouseover', d=>{ // how to get tool tip to work'title').attr('id','tooltip')
  .attr('data-date', d=>d[0])

and the link to the codepen:

CodePen is gone… did you figure it out?