We were using JIRA Cloud Confluence and changed from account. Now we would like to export the old Spaces from the old account into the new account (both Confluence Cloud).
What we did was to make an export by backup from the old site and import the original zip file to the new site. This is also how we found to do this in JIRA Cloud documentation. But we receive below error message every time:

After this we made an export for 1 Space in XML. This we can import correctly, but then the attachments are missing.
How can we export Space by Space (or multiple Spaces) with the attachments and import them>?