closing a popup via button code

Well, you didn't tried popup.close() for closing

From the manual: https://xlinesoft.com/phprunner/docs/popup_object_close.htm

Thanks it was the first I tried before the alternatives, but it doesn't work. Maybe the problem is that I want to close a popup from within the popup itself.

From manual
https://xlinesoft.com/phprunner/docs/how_to_display_any_page_in_a_popup.htm
example 7, keep the afterCreate: and do not use beforeClose. The footer has another way to close the window but returns to landing page.
var popup = Runner.displayPopup( {
url: "products_add.php", // the page to display
header: 'Add new product',
footer: '<a href="#" onclick="window.win.close();return false;">Close window</a>',
afterCreate: function(popup) {
window.popup = popup;
}
});
In popup add button and in before client add window.parent.popup.close(); return false;

You could also try this: https://asprunner.com/forums/topic/28428-Cancel-Button-via-RunnerdisplayPopup

thanks, Grdimitris solution was fine!