You need to make sure the footnote template for your chosen style and reference type, include the “Cited Pages” field (see image attached), or Citation template (if the footnote uses the citation template rather than its own from the dropdown highlighted).
In the latter, then you need to make sure the Citation template includes this field with the forced separation characters so the added comma and space do not appear when there are no Cited pages (Author, Year|, Cited Pages|).
