you can do it by yourself if you want but I thought to edit it a bit to match our device. all credit goes to original developer I just copied what he did and it worked.
I don't take any responsibility if anything happens to device, brick ect. use the guide with your own risk!
make sure you have updated drivers and a good usb cable, I recommend Smart Switch for pc you can download in the samsung site, it will also install latest drivers and you can back up the phone with it to the pc.
just for your information rooting voids the waranty, trips knox and makes things complicated, but I can't have a phone without root, it reminds me the days with my old nexus 4.
this guide will also factory reset your phone so make sure to back up everything don't forget to back up whatsapp in the app itself.
I'm not a developer maybe there is an easier way to root, this is the only way I found, so if you want to wait until an experienced developer who knows english better then me release another way to root that's fine by me, I wont get upset.
the only downside I see in this kind of root that you can't normally enter the system. I mean that normal reboot and power up will boot your system without magisk, because the root sits on the recovery or something like that. so each time you power off your phone to power it up you need to hold the Volume up + Power button untill you see the bootloader unlocked warning and release, and everything will be working with root. even if you accidently powerd your phone without the way I mentioned you still have root don't panic like I did just turn off the phone and power it up like I mentioned and its all good.
also you can't normally update the phone through the phone settings and to update the phone with odin like I understand you'll need to have a patched version of the AP tar file with magisk, or something bad will happen to the phone, again I am not a developer I don't know the full risks.
so after the warnings and the long intro here is the edited guide:
Unlock the bootloader - this will wipe all your data so make sure to back up before you start anything!
- Allow bootloader unlocking in Developer options → OEM unlocking
- Power off your device. Volume Up + Volume Down + Power button and plug in your device to a PC to boot into download mode
- Long press volume up to unlock the bootloader. This will wipe your data and automatically reboot.
the developer also mentions that sometimes it wont work because something called VaultKeeper. I didn't had that issue just make sure after the system boots after you unlocked the bootloader that the OEM unlocking option exists and grayed out in the developer options.
1.Download the firmware for your device.
2.Unzip the firmware and copy the AP tar file to your device. It is normally named as AP_[device_model_sw_ver].tar.md5
3.Install Magisk Manager from the Canary Channel
4.In Magisk Manager: Install → Install → Select and Patch a File
5.Select the AP tar file. Magisk Manager will patch the whole firmware file and store the output to [Internal Storage]/Download/magisk_patched.tar
6.Copy the tar file to your PC, and boot your device to download mode. (Hold all 3 buttons Volume Up+Volume Down+Power Button and connect to PC cable)
I have downloaded the firmware with Samfirm I found it on the forum I'll upload it here. I will also upload the AP file I patched and write the firmware version I took it from. I'll also upload the full firmware for you if you can't find a good mirror online. and also the odin version I used.
the csc i look up is for ILO but I think the csc have multiple regions, you know better I'll upload it anyway maybe it will save time for someone.
7.Flash magisk_patched.tar as AP in ODIN (I flashed the entire firmware because I had some problems flashing without all the files try it the way you want. flash it with normal csc of you choose to flash the whol firmware)
Important: Uncheck “Auto Reboot” in Options!!!!
8.Magisk is now successfully flashed to your device! But there are still several steps before you can properly use the device.
9.We now want to boot into the stock recovery to factory reset our device.
Full data wipe is mandatory! Do not skip this step.
Press Power Button+Volume Up+Volume Down to exit download mode, and as soon as the screen turns off, immediately press Power Button+Volume Up to boot to recovery partition. Just as mentioned in the previous section, since we want to boot into stock recovery, continue pressing the volume up button until you see the stock recovery screen.
10.In the stock recovery menu, use volume buttons to navigate through menus, and the power button to select the option. Select Wipe data/factory reset to wipe the data of the device.
11.This time, we can finally boot to the system with Magisk. Select Reboot system now, and immediately press Power Button+ Volume Up. After seeing the bootloader warning screen, release all buttons so it can boot to the system.
12.The device will automatically reboot for the first time it boots. This is completely normal and done by design.
13.After the device is booted up, do the usual initial setup. The following steps will need internet connection.
14.You shall see Magisk Manager in your app drawer; if not, manually install the APK you downloaded in step 3 and continue to the next step. The app would be a stub and it shall automatically upgrade to the full Magisk Manager when you open it.
15.Magisk Manager will ask to do additional setups. Let it do its job and the app will automatically reboot your device.
16.Baruh Ashem! enjoy magsik!
That's it I think if I forgot something I'm sorry I hope it worked for you! and maybe some real developers start to look at the device and start building costume roms andall the good stuff that comes with it!
meanwhile the files are uploading you can try get them by yourself here are the names of the files I used:
firmware file: SM-A705FN_1_20190412140953_u5ql0uali6_fac
Magisk manager is linked the developer enterd the canary build but I'll also upload 7.1.2.apk version I found on the internet.
ALL CREDIT GOES TO THE ORIGINAL DEVELOPER, AND DEVELOPERS. if you have any question I can help you with my own expirence only.
Here is the download link, use at your own risk. if you are not sure the firmware uploaded is right for your device download yourself with samfirm that i also uploaded.
Download Link - Google Drive