You’ll first want to make sure you are in a region where ads are supported, which you can confirm here:
Next, you’ll want to ensure you’ve gone through the available guides/documentation to ensure everything is configured correctly on your end – I would recommend starting here:
Please ensure you read the document thoroughly, as it explain what the expected ads behavior should be.
Lastly, the image you’re sharing is that of your ads history. While I believe that you haven’t seen any ads, it’s worth noting that you currently have each list (separated by date) “collapsed”. Click the arrow next to the date to expand and view the list:
Can you also share a screenshot of the Ads section in brave://rewards/ so we can see the number of ads viewed this month that is shown?