To move IMAP emails to Office 365 manually, you can follow these steps:

Set up your Office 365 account in an email client that supports both IMAP and Office 365, such as Microsoft Outlook.

Create a new folder in your Office 365 account to store the IMAP emails.

In the email client, select the IMAP account and the folder containing the emails you want to move.

Drag and drop the emails from the IMAP folder to the newly created folder in your Office 365 account.

Wait for the emails to finish copying to the new folder in Office 365. Depending on the number of emails and their size, this may take some time.

Once the copying process is complete, you can disconnect the IMAP account from the email client if you no longer need it.

Greetings,
Peter