This is an issue on your domain side, there is nothing we can help with. Your Cross-Origin Resource Sharing policy does not allow for request to the stape domain you’re trying. You should address this to your developers.
p.s. also, you should ideally be using a custom sub-domain, not the one provided by Stape
your initial query has the stape sub-domain, not the custom one. I believe you didn’t choose the correct one when generating a custom loader. So I suggest you do that first, that way there might not be any CORS issues