I can't find an option on the emulator to read the game from the disk

I installed the emulator for recommendation of a friend because my PS3 lens is starting to not read well the games.
Got an USB Bluray drive but I can't find an option on the emulator to read the game from the disk.
I heard that you can rip the games but the ISO might be very large to deal with, and that's why I rather use the drive and disks or a way too rip the games in the other formats available... if they wight less than an ISO
Thanks for any help