On the Android version go to settings/GENERAL and set a directory for the logos to be stored (use a file manager to create a folder beforehand if needed) once set back out to the main settings menu and go to ADVANCED and enable "download supposed logos", this will download the logos your provider has set up in the M3U to the previously set logos directory.
If you want to use your own logos upload them to the box and set the logos directory in GENERAL to match but don't enable the "download supposed logos" option.
If your lucky the filenames your provider uses will match your filenames, if not you will have to open the M3U in a text editor to see what names your provider has used.
When I did it I found that my provider used %20 instead of a space, so I used a renaming program to change all the spaces to %20 in my logos filenames and about 90% of the logos then worked, for the non working ones I opened the M3U in a text editor to see the exact name my provider had used and changed my logos name to match.
In a few cases there was no logo set in the M3U so I used the "Logos assign mode" under ADVANCED in Perfect Player to manually assign a logo to channel.