I'm learning to pray; is sunah rakats in duhur obligatory?

The sunnah rakahs they're not obligatory however we should try and pray them as much as we can. Why? The prophet sallallahu alaihi wasallam said that whoever prays the 12 sunnah rakahs in a day you'll get a house built for you in jannah. The 12 sunnah rakahs are: the two sunnah before fajr, four sunnah before dhuhr (there's another narration that says two sunnah before dhuhr, both authentic in sahih bukhari), the two sunnah after dhuhr, the two sunnah after maghrib and the two sunnah after isha. If you pray all of those in a day you'll get a house built for you in jannah. And every single day if you pray it you get a new house built for you in jannah. Every single time you complete those 12 sunnahs or what's known as the sunnah in a day. There are other sunnah prayers the prophet sallallahu alaihi wasallam used to pray yes, but these 12 in particular were the ones he always used to regularly pray. So try and pray it as much as we can. And we know that if there are any deficiencies in our obligatory prayer, Allah then looks at our sunnah and our nafl prayers to see if there's anything that can help make it up.