Mirror Modifier Question

Hey guys, creating a character now with mirror modifier. The problem is that the mirror doent’s work, could someone explain me how to fix it and make it work properly?

The modifier by default mirrors around the object’s origin. You either need to put the object’s origin at the center of your future character (e.g. where the 3D cursor is on your picture), or add another object there (e.g. an Empty) and set that as a Mirror Object in the modifier’s settings.

Thanks, already fixed