How to see the total network traffic usage of a Lightsail instance

I've recently created a 10-dollar-per-month Lightsail instance in the Stockholm region, and I'm on my 3-month trial period. This instance has a network transfer limit of 3 TBs per month. How may I see the total amount of traffic I have consumed in a given date range?

Unfortunately, in the Metrics section of the Lightsail website, I can only see the last-two-week network traffic in one-hour intervals, but I need the total used traffic for the current month.