Open UpgradeDownload.exe , click the Load Packet button (gear icon), and select your Nokia C20 .PAC firmware file. Power Off: Turn off your Nokia C20 completely.
The standard, free official tool for Unisoc devices. It is lightweight and can often be run without a full installation (portable mode). nokia c20 flash tool portable
While there is no single "official" portable tool from Nokia, several reliable third-party options are used by technicians: SP Flash Tool Open UpgradeDownload
