The Confluence admin can see Confluence Guest uses on the Confluence global permission guest tab
https://<INSTANCE_NAME>.atlassian.net/wiki/admin/permissions/global?tab=external
and it shows which space Guest users can access.

It would be helpful if we can export this page information to CSV.

• Guest User name
• Guest User email address
• Space (the guest user can access)

The administrator can export as follows, but this information does not include "space" information.
admin.atlassian.com > User > set Filer "Confluence" and "Guest".