Use this to create the .CIA, make sure to select the 1MB save type + RTC (its selected by default as soon as you load the rom in the Injector)
This is what worked for me!
https://www.gamebrew.org/wiki/New_Super_Ultimate_Injector_3DS
Regards!
This is what worked for me!
https://www.gamebrew.org/wiki/New_Super_Ultimate_Injector_3DS
Regards!