Question is what does extended period here mean? Does it mean 10 minutes or 30 minutes or 60 minutes?
Your specific question is answered within the article you link to in the sentence after the one where it says “exercise at a moderate level of intensity for an extended period”:
A good routine is starting with a warm up of the muscles, followed by exercising at least 20 minutes and finishing with a cooling down period to return the heart to its resting rate.
You also specifically ask:
Does it mean 10 minutes or 30 minutes or 60 minutes?
This changes as you get fitter.
When a beginner starts running, even 10 minutes will improve fitness, and might be all that some people are able to do (depends on age, fitness, weight, etc). Even 10 minutes might be too much for some people.
At the other end of the scale, experienced runners go for long runs of an hour, ninety minutes, or longer. See this article on long runs at Runner's World for some discussion.
Without knowing anything about you, it would not be sensible to suggest which end of the scale would be more appropriate.
However, it’s worth being careful when increasing weekly mileage to not increase it by more than 10% each week. And it’s also sensible to periodise training, by having an easier week every 3-4 weeks.
There are many sites that give running training programmes for people of all abilities - beginner, intermediate, advanced. Follow one of these, see how you do, and progress.
Endurance is a long-term thing. By that I mean that it can take years to get to your peak capability. It's hard to see improvements in a week or two. The worst thing you can do is try to do too much, too soon, as it leads to injuries, and if you're injured, you can't train.
So start at the low end of the scale, see how you do, and increase your time running gradually.