To convert MBOX files to PST format manually, you can use the following steps:
Open Microsoft Outlook and create a new folder in your account where you want to import your MBOX files.
Open your email client, such as Mozilla Thunderbird or Apple Mail, and select the MBOX files that you want to convert.
Copy the MBOX files to a location on your computer, such as your desktop or a new folder.
Open Microsoft Outlook and select "File" from the menu.
Click on "Open & Export" and then select "Import/Export".
In the "Import and Export Wizard" window, select "Import from another program or file" and click "Next".
Select "Outlook Data File (.pst)" and click "Next".
Click on the "Browse" button and select the PST file that you created in step 1.
Choose the option "Do not import duplicates" and click "Next".
Select the folder where you want to import the MBOX files and click "Next".
Click "Finish" to start the import process.
Outlook will begin importing the MBOX files into the selected folder. The process may take several minutes, depending on the size of the MBOX files.
Once the import process is complete, you should see all of the data from the MBOX files in the selected folder in Outlook.
Greetings,
Peter