Hello,

Please try this way:

1. Create HTML block, insert Popup element/widget, fill with the content. https://xtemos.com/docs/woodmart/shortcodes-2/

2. Then insert the HTML block in the Header builder: https://xtemos.com/docs/woodmart/header-builder/woodmart-header-builder/

You will get the button that would call the popup as soon as it has been clicked.

Best Regards