Eliminate odor for good?

I have a 10 week old puppy who stays inside. He’s had a few accidents on the carpet but I’ve always cleaned them right up and I’ve used my carpet shampooer but no matter what I do I can’t get the smell of urine out of my house. It hits me as soon as I walk in the living room. Can anyone give me any ideas to get the odor out and keep it gone? I’m new to having an inside pet (when I was younger our animals always stayed outside except in storms or freezing weather).