Inserting callout markers in Line Chart

Hi Folks,

Is there any way of being able to insert 'callout' markers or flags in a line chart?

The idea is that I'd like the ends of those callout markers to be dynamically linked to the June 2019 and March 2020 readings. (effectively assigning a marker to a data point) I'd like it so that even if the axis scales change it remains attached as per my mock up below.

Line chart with callout flag.jpg

I'd settle for a single marker but, in an ideal scenario, an ability to add additional markers would be a bonus

Would welcome any ideas

Many thanks Andy

Achieved exactly what I was looking for