Download the Samsung firmware for the Galaxy S20 SM-G981N with product code SKC from Korea (SK Telecom). This firmware has version number PDA G981NKSU1ATCT and CSC G981NOKR1ATCT. The operating system of this firmware is Android 10 , with build date Fri, 27 Mar 2020 10:58:42 +0000. Security patch date is 2020-04-01, with changelist 18334340.
AP (System &Recovery)
BL (Bootloader)
CP (Modem / Radio)
CSC_*** (Country / Region / Operator)
HOME_CSC_*** (Country / Region / Operator)
Other options in case first option did not work or isn't possible.
Option 2 VOLUME DOWN + VOLUME UP then USB cable
Option 3 POWER + VOLUME DOWN + VOLUME UP
Option 4 POWER + VOLUME DOWN + HOME BUTTON
Option 5 (Note9) USB cable + VOLUME DOWN + BIXBY
Option 6 (Note10) POWER + VOLUME UP
AP (System &Recovery)
Other options in case first option did not work or isn't possible.
Option 2 VOLUME DOWN + VOLUME UP then USB cable
Option 3 POWER + VOLUME DOWN + VOLUME UP
Option 4 POWER + VOLUME DOWN + HOME BUTTON
Option 5 (Note9) USB cable + VOLUME DOWN + BIXBY
Option 6 (Note10) POWER + VOLUME UP
For most devices, the model number (e.g. "GT-I9505" or "SM-G900F") is found inside the device. It becomes visible when you open your device and remove the battery.
As an alternative, you can also type your model name (e.g. "GALAXY S5") instead of the number. But it may be a bit more difficult to find your specific device that way.
Still not sure? Then perhaps Samsung can help you out with their model number lookup tool.