[Android Q&A, Help & Troubleshooting] rbeze:
First of all, Obi is a Chinese OEM. So the support for their products is very bad. Unlike renowned Chinese OEMs like Xiaomi and OnePlus. They never bother to release their kernel map. So most rooting apps won't work. Then they have implemented Bootloader lock, Signature Verification at boot, Secure Boot and A/B authentication and secure Ramdisk. All these are good from a security perspective. Would've been one of the most secure devices had they continued to support it by regularly patching security updates.

This was a bit of hit or miss on my part, I admit. But I'm proud and happy with the results. So let's get right to it. Follow the steps in the sequence otherwise can't guarantee whether it will work or not. There'll be video link posted. Showing the process or part of it at least. So you can use it for reference. I'm working on a custom ROM for this device as well. I'll also be porting a CWM/TWRP recovery for this device, unofficial as it's my personal project. The file lists and maps will also be uploaded for anyone who wants to help. This process also works on Obi Worldphone SF1.

Here's the video tutorial:

youtu.be/MmkaCb2C8wY

Step 1: Download Kingo ROOT 4.5.8 from the official website. Make sure your phone is charged. Close all apps running in the background using recents. This is done as the phone is very slow and underpowered. This is to help prevent it from crashing due to it's underwhelming performance.

Step 2: Click on One-Click Root in Kingo ROOT app. Wait for it. It'll be slow at 30% and 80%. Leave it as it is. Don't disturb and touch it. You'll see Rooted Successfully.

WAIT. DON'T START REJOICING NOW.

Step 3: Since the phone is Bootloader locked, what we have achieved here is a temporary root. The moment you reboot it, the root will be lost. If you want to make Payments, use apps which won't work on Root. You can leave the phone as it is. And root everytime you reboot. Following the same process. That way you'll always be able to retain that system intergrity and never lose your Bootloader locked status. The phone will be as secure as possible after a reboot. But in case, you want to keep the root after reboot and permanently root it. Follow the steps below.

Step 4: Since the Bootloader is locked, the SuperUser app can't be moved to /system/app directory. The temporary root won't allow such /system/ modifications. So to completely breach the system protection against rooting. We'll need BusyBox, Magisk Manager and XposedInstaller. Download from the official sources.

Step 5: Install BusyBox, Magisk Manager and XposedInstaller.

Step 6: Open BusyBox app and press Install. Wait for it to complete. You may notice that you were not asked to give it root/su permission. This is because of Temporary Root. It'll continue to grant all apps which require root permissions. So always be careful that you don't have harmful/malicious apps installed.

Step 7: Open XposedInstaller and install Xposed Framework. It'll reboot automatically. Once done, proceed.

Step 8: Now open Magisk Installer. There'll be two Install options one for Magisk and the other for Manager. If an update is available for the Magisk Manager from within the app, install it. It'll download to your Internal storage/Download/ directory. Install it directly or manually by going to that folder. Now install Magisk. You can choose to preserve AVB 2.0/dm-verity and force encryption if you still want to retain SafetyNet features. I'd recommend you to uncheck both else you may suddenly lose root access with no way to root it again. Hit next. In method, select Direct Install(recommended). Hit Let's go. Wait for it to complete. It'll download it from the internet then flash it. In case, you encounter, Signature Verification failed, reinstall XposedInstaller and retry.

Step 9: Will all that done, if you're greeted with Installed in Magisk. Then reboot your phone.

Step 10: Make Magisk Manager using Lucky Patcher as System App. It'll automatically do it for you. Otherwise you can use RootExplorer/ES File Explorer(first turn on Root Explorer and grant SU permission to ES File Explorer; yes this time due to successful install of Magisk it'll show a toast for 10 sec. to ask for root permissions) then go to system/app/MagiskManager (create this folder) then drag and drop the apk. Rename the apk to MagiskManager.apk and set permissions as rw_r__r__ using properties of either explorer. Then uninstall the app. Then reboot. You may need to repeat step 8 after re-rooting using Kingo ROOT app.

Step 10: After all this is done, just uninstall Kingo ROOT or leave it(In case, you choose to preserve the AVB2.0/dm-verity and force encryption, as you'll suddenly lose the root some day randomly). And you're done.

Things to keep in mind: In case, Root Unsuccessful using Kingo ROOT app. It'll ask to try using the PC Version. There's no need for it. The PC version won't work and no other ADB or Fastboot method work to unlock the bootloader of this device. Just go to app info and clear data. Then try again. This should fix the issue. You must have developer tools unlocked and ADB Debugging turned on. OEM Unlocking should be turned on as well.