Under the Theme in this regard, there is a Button with Popup style available in this regard which you can try to make use of. Here is the example defined of it: https://woodmart.xtemos.com/button-with-popup/
You can use the Theme’s “Popup” element and in that you can select the HTML Block that you want to show the content of and in that HTML Block you can add any sort of Form which you present and it might work out for you. Here is a brief Video for your ease in this regard: https://www.veed.io/view/43e29df7-46c4-454f-a5a5-6831b267cec7
Sorry to say but that Popup that you are referring to comes after adding Product to Cart which isn’t editable so right now there is no option in Theme Settings available for that. It requires Customization and this is beyond our limitations and support policy scope. Hope you can understand our limitations.