There is no such MBOX to PST Converter tool that is free of cost. Yes, free versions are available but have some limited features over purchased Softwares. Here I want you to refer MBOX Converter to export your MBOX file into Outlook. The free version of the tool can export some of your emails to PST. You can also purchase the software from the official site. Visit here to download the free version:-
https://www.osttopstapp.com/mbox-to-pst.html