You cannot update what you do not know. First, check which version you are currently running.
: Visit the official website of your router manufacturer or your service provider (such as Delta/Zeelandnet ) to download the latest firmware file. Access Admin Page Update Software in SAGEMCOM F-ST 3890 V3 Delta
Cybercriminals constantly scan for routers with known vulnerabilities. Outdated firmware is a goldmine for botnets (e.g., Mirai variants) and DNS hijackers. Each update patches known entry points. You cannot update what you do not know
Use this method if automatic update fails, you have no internet, or your ISP provided a file. you have no internet