The following license & roles are mandated to perform tenant-tenant Microsoft Forms Migration for both Source & Target Connector Accounts.
Additional permissions required :
To migrate a Group Form, both Source & Target Connector Accounts must be a member of the Group the form belongs to.
To migrate a User Form,
i. Microsoft 365/Office 365(E3 or E5) License is required for the source & target users whose forms are migrated
ii. User Administrator Role is required for Source Connector Account
iii. Both Source & Target Connector Accounts must have Secondary Admin access for users whose forms are migrated