List Filter frappe from the doctype list page

1

frappe.listview_settings[‘Candidates’] = {
onload: function(listview) {
listview.page.add_inner_button(__(‘Assign Selected Candidates to Classes’), function() {
let selected_candidates = listview.get_checked_items()
.map(item => item.name); // Get selected candidate IDs

        if (selected_candidates.length === 0) {
            frappe.msgprint(__('Please select candidates to assign.'));
            return;
        }

        open_assign_candidate_dialog(selected_candidates);
    });

    let search_input = $(`<input type="text" id="milvus_search" 
        placeholder="Search Candidates..." class="form-control" 
        style="margin-left:10px; width:200px;">`);

    // Append search input to the List View header
    $(listview.page.wrapper).find(".layout-main-section .list-row-head").prepend(search_input);

    // Handle search when the user removes focus (onblur)
    search_input.on("blur", function () {
        let searchText = $(this).val().trim();
        if (searchText) {
            search_candidates_in_milvus(searchText);
        }
    });
}

};

function search_candidates_in_milvus(query) {
frappe.call({
method: “custom_app.custom_app.doctype.candidates.candidates.search_candidates”,
args: { query: query },
callback: function (r) {
if (r.message) {
console.log(“Search Results:”, r.message);
update_list_view(r.message);
}
}
});
}

// Function to Update List View with Search Results
function update_list_view(candidate_names) {
if (!candidate_names.length) {
frappe.msgprint(__(‘No candidates found.’));
return;
}

let first_names = candidate_names.map(name => name.split(" ")[0]); // Extract first name
setTimeout(() => {
    frappe.set_route('List', 'Candidates', {
        'first_name': ['in', first_names]
    });
}, 500);

}
why i am not able to set filters please help. Not able to set filter when i am at the candidates doctype list page