Search for: “Nokia G21 Punisher MT6765 stock firmware”
Backup: Flashing will erase all data. If possible, backup your photos, contacts, and documents. Step-by-Step Guide to Flashing the Nokia G21 nokia g21 flash tool full
Because the Nokia G21 uses a Spreadtrum/Unisoc chipset, standard "SP Flash Tool" versions (which are for MediaTek) generally will not work. Instead, technicians often use: SPD Flash Tool (UpgradeDownload/ResearchDownload) Search for: “Nokia G21 Punisher MT6765 stock firmware”