Fitrah
Fitrah (فطرة) is a term in Islamic theology which has many interpretations. The most popular interpretation today is that it's a natural human disposition to believe in Islam.
Quran
The word fitrah is usually translated as "nature" without looking at other words derived from the same root.
There are 20 words from the root فطر in the Quran and the vast majority carries the meaning of "creation", not "nature" [1]. Allah himself is called faatir (فاطر) many times (it's also a name of sura 35) and it was translated as "creator" or "originator".
The word فطرة can be found in the verse 30:30 if we read the Quran in the modern Arabic script. But in the older Uthmani script it was written as فطرت (fitrat) with the letter ت and not with the letter ة.
Uthmani script: فَأَقِمۡ وَجۡهَكَ لِلدِّينِ حَنِيفٗاۚ فِطۡرَتَ ٱللَّهِ ٱلَّتِي فَطَرَ ٱلنَّاسَ عَلَيۡهَاۚ لَا تَبۡدِيلَ لِخَلۡقِ ٱللَّهِۚ ذَٰلِكَ ٱلدِّينُ ٱلۡقَيِّمُ وَلَٰكِنَّ أَكۡثَرَ ٱلنَّاسِ لَا يَعۡلَمُونَ
Imla'i script: فاقم وجهك للدين حنيفا فطرة الله التي فطر الناس عليها لا تبديل لخلق الله ذلك الدين القيم ولكن اكثر الناس لا يعلمون
Sahih International: So direct your face toward the religion, inclining to truth. [Adhere to] the fitrah (فطرة or فطرت) of Allah upon which He has created (فطر) [all] people. No change should there be in the creation of Allah . That is the correct religion, but most of the people do not know.
It's worth noticing that it literally says فطرة الله ("nature of god"). So god created people upon his nature. And also notice that the word "created" is فطر (fatara) which is from the same root as fitrah.