Slippi only works with the 1.02 NTSC .iso.
Don’t settle for PAL. Don’t settle for 1.00. The meta lives at 1.02. 1.02 ntsc ssbm .iso
In practice, most online players have downloaded the .iso from preservation archives. Emulation laws are complex (DMCA exemptions for abandoned hardware exist), but ethically, you should only download the file if you own the original disc. Slippi only works with the 1