Trying to do the migration thing as requested and instructed, but falling at the first hurdle...
"Click Settings and go to Admin Panel" - except that when I click Settings, all it offers me is Connected Devices and Storage Details. I'm using a free version of Zoho [we're NFP] through Firefox on win10.
I can get to an Admin Console [?] [?is this the same thing?] via Settings on Mail but that doesn't have the migration tab referred to, and, of course, that's the admin for ZMail not ZDocs