iOS unzipping a file?

I am trying to use the PPSSPP emulator on iOS and when I try to load the game into the app, it tells me I need to unzip the file first, but the program to use isn’t on mobile, or at least not iOS and don’t know how to unzip files for use on the PSP emulator. Trying to play the PSP version of Crash Tag Team Racing and don’t know how to properly load it into PPSSPP.

"New to emulation entirely"