The first scribe to write a revelation of the Holy Prophet (sa) after his migration to Medina was Hazrat Ubayy (ra) bin Kaab. At the time, it was not common for the scribe’s name to be written at the end of a Quranic inscription; however, Hazrat Ubayy (ra) initiated this practice and the other companions also adopted this practice.
(Ali Ibn al-Athir, Usd al-Ghabah fi Ma‘rifat al-Sahabah, Vol. 1 [Beirut, Lebanon: Dar al-Kutub al-Ilmiyyah, 2016] 170) (Sheikh Shah Moinuddin Ahmad Nadvi, Siyar al-Sahabah, Vol. 3 [Karachi, Pakistan: Dar al-Ishaah Urdu Bazar, 2004] 158)
Meaning, the name of the person who had inscribed the text would not be written, rather the text would simply be written out [without any indication of who transcribed it]. Hazrat Ubayy (ra) began signing his name at the end of an inscription to make it known that it had been written by him, and thus, it became common practice.