How do I add more shaders? (Latest Android version)

[RSM777]

I was mainly using PPSSPP on my Xbox Series S, and I was using XBRZ4 shader + scanlines, and it looked really good IMO.

Recently got a Retroid Pocket 3+ and installed PPSSPP, and although CRT scanlines looks good for older games, it doesn't look as great for 3d games or newer pixel art games, so I just wanted plain old scanlines without the CRT effect.

Problem is, I just can't find the shaders/filters folder inside my device. How can I add new shaders aside from the default ones on the android version?

Thanks in advance.