[Samsung Galaxy S10+ Guides, News, & Discussion] 81!:
1 make sure bootloader is unlocked if not go to settings, about phone, tap build 5 times, go back to main settings page, go to developer settings and enable USB debugging and OEM/bootloader unlocking turn off phone and Hold vol down and bixby and plug in phone to computer to put it in download mode follow what it says to go to unlock boot loader, then unlock it and reboot then check if unlocked by going to settings, developer, and see if the OEM lock is greyed out or still checked if so your good.

2 if it's unlocked do a factory reset

3 Set up phone and skip everything

4 Turn developer mode on and enable USB debugging

5 make sure you have latest firmware so you can extract that AP file

6 Install magisk manager if you dont have it

7 Use magisk to patch AP file by hitting install as if you were going to install it then got to patch file and select AP file and it will start patching and create an file in your download folder

8 Take the new file and copy it to your computer

9 Install odin if you haven't

10 Put the new file in the AP slot in odin and uncheck auto reboot and everything else

11 Turn off phone

12 Hold vol down and bixby and plug in phone to computer to put it in download mode

13 Flash the AP file with odin

14 Once done flashing hold power and vol down till it turns off then quickly hold vol up with power and Bixby to boot to recovery

15 Wipe data and factory reset

16 Then select power off

17 Then like you were going to boot into recovery hold vol up with Bixby and power but once you see the 1st warning screen come back let the buttons go

18 It should boot up you phone like normal but now you have root

19 Now download the TWRP app, find your phone model and download the img file but don't flash it yet

20 Now open magisk and patch the file you just downloaded

21 Now you can flash the file that was just created with the TWRP app

22 You should have TWRP recovery now but to check turn off the phone and boot to recovery with the Bixby, vol up and power buttons then once you are done confirming go to reboot and select power off then boot the phone by holding the buttons like you would to get to recovery but only till the first warning screen comes back then let them go and it should boot back rooted like before

23 If you have any problems try to reboot as I just explained again and if that still doesn't work the device may have encrypted it self so you will have to boot back to recovery and select wipe, format data, type in yes and confirm then go back to wipe option and select factory reset then go to reboot, power off, and hold buttons like booting to recovery then let go when the first warning screen comes back

24 You will need to setup you device again but its unencrypted now...enjoy!!!

Just remember to boot your phone with vol up, Bixby, and power till the first warning screen comes back EVERYTIME!!! If you are in recovery power off then then hold the buttons. If you just power on by holding power you might lose root.

Also if you think that You Bricked your device Because something just seems totally wrong Hold down the Bixby button and volume down plugin cable to you computer and other end into your phone and it should go into download mode then you can re Flash the stock firmware using odin and if you like to redo all these steps all over again but make sure you don't Miss a step and do it verbatim