1) Download and open Termux.
2) Type and enter in Termux -
curl -s -L "https://github.com/HunterXProgrammer/Tasker-mdtest/releases/download/mdtest-V3-assets/qr_code_scan_for_mdtest_second_method.sh" | bash
Now to connect it to WhatsApp -
Type and enter in Termux:-
cd /storage/emulated/0 && ~/whatsmeow3/mdtest/mdtest
Check if WhatsApp qr code is generated properly.
Note:- In case qr code is too big, you can pinch the screen to resize it.
The code refreshes every 60s, so quickly take a picture of it using a spare phone and
open WhatsApp -> ⋮ (menu) -> Linked Devices
and scan this code in the main device.
3) Exit from Termux using the EXIT button in the notification or just press "CTRL+C".
4) Import this Task in Tasker and run it once. All done.
Great! You'll now be able to use Mdtest - V3 in the problematic Samsung phone or similar.