To convert an OLM file to PST on Mac, you need an application that can read the Mac Outlook OLM structure and export its mailbox data into the PST format. The basic process involves loading the OLM file, examining its mailbox contents, selecting the required folders or items, choosing PST as the output format, and saving the resulting file to a selected location.

The SysInfo Mac OLM Converter provides these options in a straightforward workflow. After launching the application, add one or more OLM files from your Mac. The software can process individual files as well as multiple OLM files in bulk. Once the OLM data is loaded, use the preview panel to view the available mailbox folders and select the data required for conversion. This can include emails, contacts, calendars, tasks, and notes.
Read more: https://www.sysinfotools.com/mac/olm-converter.php