How is the national electoral register created?

Kuwait Times, Al-Hajri: All 21-year-old Kuwaitis eligible voters in 22 parliamentary elections [22-08-2022], accessed 17 January 2023

See also this article. 

In 2022 Elections, Kuwaitis could vote using their civil ID cards. Previously, the voters lists were prepated by the Ministry of Interior and updated annually. The change implemented in 2022 indicate that the voters' lists are now based on civil registry.