The JC-22 is compatible with the following footswitches:
Connect using a 1/4" TS mono instrument cable for FS-5L, or 1/4" TRS stereo cable for FS-6 / FS-7.
You can also use an effect switcher (ES-8, ES-5) to switch amp channels. See "Switching the Amp's Channels" in the ES-8 or ES-5 Owner's Manual for correct set up.