Installing a custom ROM requires an , which is the gatekeeper for third-party software like LineageOS.
Since a full custom ROM is currently unfeasible for most users, you can achieve similar results through these methods: GSpace / GBox: Use these apps from the Huawei AppGallery
The concept of a "cracked" or "custom ROM" for the Huawei MatePad 10.4
to run Google apps like Maps or YouTube in a virtual environment. Debloating : You can use ADB (Android Debug Bridge)
fastboot --disable-verity --disable-verification flash vbmeta vbmeta_disabled.img