How to change icon size of folder tree

How to change icon size of folder tree?
Default size is small and hard to pick them, I know I can change the font size of folder tree, but I don't know how to change the icon size.

The icon size in the folder tree is decided by Windows. It can be increased by increasing the system-wide scaling factor, in the Windows Display settings panel. That will increase the size in Opus and everything else, if it is too small for you.

thanks