Unlike Samsung or Xiaomi, Nokia devices (especially those running Android One/stock Android) rely primarily on and the SP Flash Tool . There is no "Nokia Suite" for the G21. Instead, you use the industry-standard tool for its MediaTek Helio G37 processor.
Here's a general step-by-step guide on how to flash the Nokia G21 using a flash tool: nokia g21 flash tool full
Once the process shows a "Passed" or success message, disconnect your phone and power it on. It may take a few minutes for the first boot to complete. Troubleshooting and Support Download SP Flash Tool for Nokia phones Unlike Samsung or Xiaomi, Nokia devices (especially those