On the PS Vita, PBP files are run using , a software environment that emulates the entire PSP architecture.
For troubleshooting specific handhelds or setups, these communities are excellent resources: pbp psx roms
While almost every modern "Retro" handheld (RG35XX, Retroid Pocket, etc.) supports PBP, some very old or niche emulators might still prefer the classic BIN/CUE format. How to get them? On the PS Vita, PBP files are run