Can't allow Flash

I need to have Flash installed and activated to view HBO but my Safari doesn't recognize the Flash I just downloaded and installed.
I restarted Safari twice but still the same. The only advice I can find is "allow Flash under the Websites tab in Safari preferences" BUT my version of Safari (10.1.2) doesn't have a "Websites" tab.
So, where can I find the place that does allow Flash to run in Safari now?