From WordPress admin menu go to Shortcode Generator => Layout select any Isotope layout then it will category filter layout
1) Layout: Select any Isotope layout from the layout list.
2) Isotope Filter(Selected Item): You can set which category will be select by default “Show All” button will be selected.
3) Isotope Filter (Show All item): IF you want can hide the show all button and select a category button as default filtering.
4) Isotope Search Filter: You can enable the search field in Isotope filter button line.
Note: Others Shortcode Generator settings as usual or you can change as your need