I just noticed that you mentioned Web Designer 10. That is very old and there was no on-line catalogue at that time. One did have to purchase the templates separately. IIRC, the on-line catalogue started with version 11 and templates were included with one-year access to the on-line catalogue.
I think you need to ask your question direct to Xara Support rather than here in the magix user to user forums.
Since you have the subscription version, which I understand Magix no longer offers, I suspect no-one who posts or visits here regularly will be able to offer you any advice in addition to what @SP. has suggested.