Lg g3 6.0 OTG problem

Hi just flashed 6.0 on my lg g3 d855, it does support otg,but my problem is i store ppsspp roms (.iso) in my otg usb but none of the explorer able to open .iso file in ppsspp,and ppsspp doesn't recognise otg,so is there any way i can able to access .iso for ppsspp via otg only.i use sd card and internal storage only for my pictures and videos, Only due to this problem i flashed lollipop again:( . Its on every device with marshmallow 6.0

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