Thanks for contacting us and choosing our product!
We checked your site but can’t login: https://prnt.sc/aydJft_8a6EM
However this issue may happen when you missing image when import demo data.
However you can delete all old product then go to WC Designer Pro -> Documentation -> Demos and re import demos: https://prnt.sc/zT1QMylvAGu5
You also can see how to setup customizable product in the document: https://document.harutheme.com/pricom/ (section 11)
Hope this helps!