devices with MediaTek (MTK) chipsets, an (Authentication File) is a specific digital certificate required by tools like SP Flash Tool to bypass secure boot restrictions
This is the hardest part. Infinix does not publish these files officially. They are distributed only to authorized service centers using tools like SP Flash Tool 5.xxxx (Infinix Authorized Version) and Infinix Smart Phone Flash Tool. Infinix MTK DA Auth File
Critical Warning: Free auth files found on random forums are often blacklisted or partially signed. Using a revoked auth file will still produce an authentication error. You need a currently valid Infinix MTK DA Auth File. A Windows PC: (Windows 7/8/10/11)