To be able to Root Samsung J4 SM-J400G using Magisk, we must first install a custom TWRP. The easiest way to root Android right now is to use Magisk or SuperSU, while the online root method, such as the King Root application, generally fails or doesn't work.
How to Install TWRP Samsung J4 SM-J400G?
You can read my previous article entitled: How to Install TWRP Official Samsung J4 SM-J400G. after we have successfully installed TWRP and the no-verity-opt-encrypt. 6.1 files the next step is to install Magisk.
First, please install the latest version of Magisk here: Free Download Magisk Latest Update. After that, just install Magisk.
After you install Magisk, just select the Reboot System option, then the Android screen window will display the Magisk Application Icon and congratulations Android Samsung J4 SM-J400G is now rooted.
Try opening the Magisk Application, then Magisk will automatically download the latest system. If you fail, just install Magisk Manager then Updates.
This is more or less what the latest version of the Magisk application looks like today. If you are still curious and want to make sure whether your Android Samsung J4 SM-J400G is really rooted, try downloading Root Checker on Playstore.
That's the Tutorial Guide How to Easily Root and Install Magisk Samsung J4 SM-J400G that you can try to practice.