A complete flash file for the Nova 5T (YAL-L21) contains the following partitions in either (for recovery flashing) or scatter-loader format (for low-level flashing):
Clearing deep-seated system lag or corrupted data that a standard factory reset cannot fix. Essential Components
Sign out of your Google (FRP) and Huawei IDs to prevent lockout.
This method works well if your bootloader is unlocked or if you are using the modified recovery method.