If you manage to obtain an unlock code, the process follows these standard steps:
Unlocking and installing a custom ROM on the Huawei MatePad 10.4 is exceptionally difficult because Huawei ceased offering official services in 2018. Because an unlocked bootloader is a strict prerequisite for flashing custom firmware, the "exclusive" custom ROM scene for this device is virtually non-existent. The Current State of Custom ROMs huawei matepad 104 custom rom exclusive