You can define this in the RecolizeParameters JavaScript object in your domain’s advanced configuration under “Add additional JavaScript code to execute before Recolize initialization”:

RecolizeParameters.Position = {
    1: {
        Carousel: {
            responsive: {
                668: {
                    items: 3
                }
            }
        }
    },
    2: {
        Carousel: {
            responsive: {
                668: {
                    items: 3
                }
            }
        }
    },
    3: {
        Carousel: {
            responsive: {
                668: {
                    items: 3
                }
            }
        }
    }
}

1, 2 and 3 are the positions. If you need more positions per page, then just define more position objects.

The standard responsive breakpoints are:

0: {
    items: 2
},
360: {
    items: 3
},
668: {
    items: 4
}
How can I change the number of displayed items in the carousel?