If you have enabled the “Use Pop-up Filter widget” for mobile devices, but do not see the button to open this widget on your phone or tablet, it is likely that your theme does not yet support the automatic display of this button.
However, starting with version 1.1.0 of the Filter Everything plugin, you can add it yourself using the shortcode:
Insert this shortcode into the widget you are interested in and check its appearance on the mobile device (on desktop devices this button is always hidden). If all is well, you should see a button marked in red in the screenshot.
If this button still doesn’t appear, make sure that:
- the Filter widget is generally displayed on this page, i.e. whether it is displayed on the same page on the desktop device.
- make sure this widget area isn’t hidden on mobile devices. For example by adding a text widget with any content.