: This site maintains a repository of stock firmware files for various ZTE models, including flashing instructions.
: The official ZTE Global Support Page provides the BLADE A55 SD card software (MyOS14.0.3_Z2450_EEA) for manual updates via SD card. zte blade a55 firmware link
Because the ZTE Blade A55 utilizes a Unisoc chipset, standard Android tools like SP Flash Tool (which is for MediaTek) generally will not work. : This site maintains a repository of stock
: You can also download the ZTE Blade A55 Quick Start Guide and English User Manual from the same official support site. Third-Party Flash Files (Stock ROM) verified software directly from ZTE.
Go to Settings > System > System Updates . This is the only way to get official, verified software directly from ZTE.