Quick solution for PST to Office 365
Microsoft provides the Network Upload Method by this manual way you can import PST to Office 365. But if you are searching the instant solution then I recommend you the A2Z Migrations for PST to Office 365. It is the best software for transferring the Outlook PST data with all emails, contacts, calendars, appointments, attachments, and tasks, etc into o365 Cloud Platform. This PST to Office 365 Migration Tool available in the market at a very reliable cost starting from $10.14 for per mailbox.
You can migrate your Multiple PST data into multiple Exchange Online environments with or without Impersonation rights. This application allows the CSV option for the multiple Migration but you can also manually type the account details.