The parameters for a request depend on the request type.
For example, for requests to migrate from data files having PST, EML or MBOX data, you have to specify the file co-ordinates and the details of the destination account to which the data has to be migrated.
For a request to migrate from IMAP servers, the request details will include the access credentials of the IMAP account and the account to which the data has to be migrated.