Then use Startup Disk Creator again and it should auto-format the drive!.
If you can; I recommend that you download a fresh ISO and start completely from the beginning again!, that is of course up to you. If you do download a fresh ISO, download it from a different location than the last one you downloaded!.
Most likely the same as above?:
You can also try Unetbootin but it requires a FAT32 pre-formatted USB stick!: