The scatter file is mandatory. It uses the region field to decide if a partition goes to EMMC_BOOT_1 (preloader) or EMMC_USER .
Despite following the steps correctly, you may encounter errors. Here are the most common issues with MT6769 scatter files and how to resolve them. mt6769 scatter file
[Extract Firmware] -> [Open SP Flash Tool] -> [Load Scatter] -> [Bypass Auth] -> [Flash] The scatter file is mandatory