Here's a step-by-step guide using SP Flash Tool:
Search for the "itel A11 Flash File" compatible with your specific build number. Most itel A11 devices run on the Spreadtrum (SPD) chipset. itel a11 flash file upd
Flashing is the process of overwriting your phone’s existing operating system with a clean, new version. It’s a "nuclear" fix that can solve: Here's a step-by-step guide using SP Flash Tool: