hi @pintas, welcome to this forum.
follow this instructions :
https://xdaforums.com/t/recovery-official-3-6-1-x-twrp-for-galaxy-s20-s20-s20-ultra-exynos.4441701/
to unlock the device, and flash a “custom-recovery-manager” even if you prefer to replace TWRP by the “recovery-e” included in the .ZIP.
also :