There are 7 columns:
Site_id, Date, Campaign_id, Ad_type, cumulative_impression_delivered, cumulative_actual_impression_goal, Delta
I have created a card in table format using all the above columns and trying to set an alert on Delta column whenever it reaches to the threshold but I am getting below message while setting up a rule.
Set up your alert rule
No alertable metrics found on this card. Please add a Summary Number or change chart types and try again.
I'm not really sure how to correct my chart to get this alert set up? Please help.