LG f370s ( g2 mini ) can’t download mode

i unlock ok by octopus but service disable. I try to root by PurpleDrake-Lite then can not boot device into download mode. I try to flash the device by converting files from file oct get tot but could not convert octopus box device into download mode is. I tried to download mode by vol + g2 insert mini usb but the screen only displays the words
"lOADING .Press the volume up key untill you see the download screen"
I think my g2 partition loss is (download mode) but I do not know how to fix it.
Please help.