I have deployed and migrated the users to O365 online. Please find the below steps that I will follow to migrate users.
1. In EAC, go to Office 365.
2. Under Recipients > Migration, click Add +, and choose Migrate to Exchange Online.
3. Select Remote move migration on the Select a migration type page; click Next. It will take you to the Select the users page.
4. Click Add+. Here you can select the on-premises Exchange users you want to migrate to Office 365. Click Add, then OK, and then Next.
5. Input the credentials of on-premises administrator on the Enter the Windows user account credential page.
6. Ensure that your on-premises Exchange Server (FDQN) is listed on the Confirm the migration endpoint page, and click Next.
7. Create a migration batch on the Move configuration page by providing the required details; click Next in the end.
8. Finally, at the Start the batch page, choose one recipient to receive the report after the batch completion. Check the Automatically complete the migration batch box. Click New.
Note: After the completion of the migration, batches can be deleted (this can be done from Recipients > Migrations).