If you need to convert MBOX to Outlook PST there are two solutions for this One being manual way & the other is a third-party solution. The manual techniques consume a lot of time & the process is also very cumbersome.
So, I would suggest you go for a third-party solution. I have tried MBOX to PST Conversion. This is an efficient software to easily migrate MBOX files to PST file format.
This Application Supports MS Outlook 2003, 2007, 2010, 2013, 2016, 2019. It also supports all Mac OS & Windows versions. You can also try the free trial version, With the help of this trial version, you can move the first few items per folder.
For more info visit here:- https://www.toolsbaer.com/mbox-to-pst-conversion/