Migrating from Outlook.com to Microsoft 365 Business Basic

I am currently testing Microsoft 365 Business Basic.
My users mail boxes are all on Outlook.com. I need those mailboxes migrated to Microsoft 365 Business Basic.
This seems impossible as PST files are not supported by that subscription and IMAP is not supportes either.

What are the right way to migrate users mail boxes from Outlook.com to Microsoft 365 Business Basic?