If you want to repost this internal OTA to other websites (other than XDA itself), please ask me for permission, thanks.
This is early internal test build, so LATER OTA UPDATES CAN'T BE GUARANTEED!
If you don't have unlocked bootloader, you'll unable to roll back to stable build!
Please be careful when testing!
Internal build version: CTL-4040-0-00WW-B01
It will be updated from: CTL-354K-0-00WW-B01, which is not pushed to public
As I've warned before - having an unlocked bootloader is strongly recommended.
So recent builds removed handy 874 dialing codes, we have to install them under recovery or Nokia Extensions.
Let me tell you how to verify:
1. Dial *#*#227#*#* to check current Version. If older than CTL-354J-0-00WW-B01 (check if the letter is greater than J), update to 354J before proceed.
FYI, 354J is August 2019 Security Update.
Alternately, you can use command "fastboot oem getversions" under fastboot mode / Download mode to check current firmware version.
If newer than 354J (probably 354N when this post released), you'll need to downgrade your phone back to at most 354H - which can't be done easily without unlocked bootloader.
2. Install CTL-354K-0-00WW-B01-354J-0-00WW-B01-update.zip with Nokia Extensions OTA Update module or adb sideload under recovery.
3. Reboot your phone.
4. Install CTL-4040-0-00WW-B01-354K-0-00WW-B01-update.zip with Nokia Extensions OTA Update module or adb sideload under recovery.
5. Reboot your phone.
If minor fixes released, I will upload them as well, then use the same method to install it.
To root the phone, you may want to use Magisk 20 released October 12th, 2019 or newer.