Polochon31

Hello everybody. Sorry if this type of topic already exist but i don't find in the forum. I've a FX100 who work good. The only thing is that i've to plug my amp (Fender) on the Main out (left or right) or Phone to use it. If i plug my amp on the "AMP OUT" i've no sound. On my amp i've only one "INPUT". Any idea ? Thx by advance