You cannot install a without TWRP. Here is the condensed workflow:

The Samsung Galaxy A9 (2018) is a classic device with unique hardware. Custom ROMs like LineageOS or crDroid can extend its life by years, delivering modern Android features. However, the trade-offs—permanently tripped Knox, degraded camera, and potential banking app issues—are significant.

This ROM is ideal for users who want their Samsung to look and feel like a Google Pixel, complete with Pixel-exclusive features and the Google Sans font.