I have been trying hard to research on this. Magisk requires unlocked bootloader but my 5833 is Bootloader that cannot be unlocked (as indicated). So I was trying to access 575 to allow me to install custom recovery. No?
Follow this guide exactly. It clearly walks you step by step through the 575 flash method on the first page here. You will see that the Kernel files need to be renamed after downloading. Some other things unclear on this thread are explained better.
chmod: /data/local/tmp/mm_twrp_recovery_install/install_twrp_recovery.sh: Not a directory chmod: /data/local/tmp/mm_twrp_recovery_install/iovyroot: Not a directory
cannot stat 'boot_twrp_recovery.sh': No such file or directory cannot stat 'busybox': No such file or directory cannot stat 'byeselinux.ko': No such file or directory
If you've got TWRP or CWM recovery installed, you can see if creating a pre-rooted Android 6.0 will work: https://forum.xda-developers.com/crossdevice-dev/sony/tool-prfcreator-easily-create-pre-t2859904