Need some help with UI too small

[Messy71]

On a 15.6" 4K display the UI is too small.

The Fractional Scaling is set to 225%.

Need some guidance for fixing this, I've tried to use QT_SCALE_FACTOR = 2.75 or GTK_DPI_SCALING=2.75 but i don't know where to set the properly or which to use.