1. Download the firmware Galaxy A50s that match with your A50s Model number.
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. Copy 3. AP tar file and MagiskManager.apk to your phone.
3. Install Magisk Manager on your phone
4. Open Magisk - Settings - Update Channel select Custom in the custom URL write "https://github.com/topjohnwu/magisk_files/raw/3dec54c8a850660e3420f7668c7fb6dc8f7c199b/stable.json" then refresh Magisk by switch down the screen.* You will see Latest magisk is v19.3.
5. In Magisk Manager: Install → Install → Select and Patch a File
6. Select the AP tar file. Magisk Manager will patch the whole firmware file and store the output to [Internal Storage]/Download/magisk_patched.tar. Copy magisk_patched.tar the tar file to your PC
7. Reboot to Bootloader: Turn Power Off. Press and hold Volume Up key + Power Key, When Samsung Logo appears release Power Key only, keep pressing Volume Up key until Android Recovery Mode Appears. Select Wipe data / Factory reset. Select Reboot to bootloader. Connect the phone to PC using USB Cable.
8. Make sure the boot loader are unlocked ( OEM options is enabled with grey color )
9. Flash magisk_patched.tar as AP in ODIN, together with the BL, CP and HOME_CSC files.
Important: check “Auto Reboot” and "F. Reset time" only in Options!
10. Magisk is now successfully flashed to your device!
11. After the device is booted up, do the usual initial setup. It need more time and patient.
12. Connect the phone to Internet, if you see Magisk Manager installed, you must uninstall it.* Then Copy Magisk Manager apk file to your phone and install it.
13. Open Magisk Manager. It will ask to do additional setups. Let it do its job and the app will automatically reboot your device.
14. Done! Your phone root with Magisk v19.3, Enjoy!
Magisk v19.3 worked stable on Samsung Galaxy A50s, watch this video below for visual guide