Apply Parent page to all odd/even pages?

Hello I got this script to work for me - it allows you to select which Parent Page is applied to Even or Odd Pages

Let me know if it's ok or if you need any tweaks

https://creativepro.com/how-to-install-scripts-in-indesign/

(function () {
    var doc = app.activeDocument;
    if (!doc) {
        alert("No active document open.");
        return;
    }

    var parentNames = doc.masterSpreads.everyItem().name;

    if (parentNames.length < 2) {
        alert("You need at least two parent pages to apply this.");
        return;
    }

    // Show the dialog
    var dlg = new Window("dialog", "Apply Parent Pages to Even/Odd Pages");
    dlg.orientation = "column";
    dlg.alignChildren = "left";
    dlg.spacing = 10;
    dlg.margins = 16;

    dlg.add("statictext", undefined, "Choose parent pages:");

    var evenGroup = dlg.add("group");
    evenGroup.add("statictext", undefined, "Even pages:");
    var evenDropdown = evenGroup.add("dropdownlist", undefined, parentNames);
    evenDropdown.selection = 0;

    var oddGroup = dlg.add("group");
    oddGroup.add("statictext", undefined, "Odd pages:");
    var oddDropdown = oddGroup.add("dropdownlist", undefined, parentNames);
    oddDropdown.selection = 1;

    var btnGroup = dlg.add("group");
    btnGroup.alignment = "right";
    var okBtn = btnGroup.add("button", undefined, "Apply");
    var cancelBtn = btnGroup.add("button", undefined, "Cancel");

    okBtn.onClick = function () {
        dlg.close(1);
    };
    cancelBtn.onClick = function () {
        dlg.close(0);
    };

    if (dlg.show() !== 1) {
        return; // User cancelled
    }

    var evenName = evenDropdown.selection.text;
    var oddName = oddDropdown.selection.text;

    app.doScript(function () {
        var evenParent = doc.masterSpreads.itemByName(evenName);
        var oddParent = doc.masterSpreads.itemByName(oddName);

        if (!evenParent.isValid || !oddParent.isValid) {
            alert("One or both selected parent pages are invalid.");
            return;
        }

        var pages = doc.pages;
        for (var i = 0; i < pages.length; i++) {
            var page = pages[i];
            var pageNum = page.documentOffset + 1;

            if (pageNum % 2 === 0) {
                page.appliedMaster = evenParent;
            } else {
                page.appliedMaster = oddParent;
            }
        }
    }, ScriptLanguage.JAVASCRIPT, undefined, UndoModes.ENTIRE_SCRIPT, "Apply Parent Pages to Even/Odd");

    alert("Done! Parent pages applied to even and odd pages.");
})();