The .bin file specifically acts as a modified configuration backup. When uploaded to the router’s management interface, it bypasses factory restrictions to grant and unlock the SIM slot for universal carrier use. How to Use the Unlock File
: If you prefer a safer, official route, third-party services like DirectUnlocks offer IMEI-based unlocking that doesn't require manual file flashing. Download File unlock-ZLT-P21.bin
Router Firmware - Download Software and Firmware - 1 - Manula.com Download File unlock-ZLT-P21.bin