First, click on 'Not Secure' in the address bar:
After doing so you will see the below, click on 'Site Settings'
A page will open in a new tab, Look down the list until you find 'Flash'
Note the dropdown list currently says 'Block' click on the list and select 'Allow'
You can then close that tab off. On the original tab you will now see a new bar at the top. Click on Reload:
The bar will disappear and it will look like nothing has happened. Close the browser and reopen the page and it will then work for you