How to add data driven annotation to a line chart

I'm trying to create a dashboard in Qlik using vizlib line chart for monitoring anomaly detection in some trend KPIs. Here is my data columns: 

alarm_comment, flag (which has a binary value), metric_value, year_month_date

The dimension is [year_month_date]. The measure is [metric_value]. What I need is to show annotations for the dates that have the FLAG=1, I did the following but it doesn't add any annotations to the line chart:

Also, although in the screenshot the value for Value on x-Axis, Measure value and Title are different, when I open expression editor, the 'Field' is 'alarm_comment' for all 3 of them (second picture). Could that be the issue?