Now you can easily import OLM to Mac Mail using the tool vMail OLM Converter for Mac. Using the tool import all Outlook for Mac emails or selective email files to your Mac Mail account. The tool has an MBOX format as well as an IMAP option. Either convert the OLM files to MBOX format or import the OLM files to Apple Mail directly using the IMAP option.

Know more info- https://www.vsoftware.org/olm-to-pst-converter.html
Are you looking for an instant solution to export OLM files in PST? If yes then use OLM to PST Converter. The tool is accessible to all Windows edition such as 10, 8, 7, 8.1, Vista, XP, etc. It has simple and non-tricky working steps that provide quick OLM to PST conversion. The tool is capable of saving all items such as emails, contact, calendar, attachments, etc. from Mac Outlook to Outlook. To grab more info download demo edition of OLM to PST Converter. Refer:- https://www.gaintools.com/olm/pst/
Manual technique: OLM to PST conversion
Open Gmail or any other webmail then, click on Settings.
In Settings, select Forwarding and POP/IMAP tab.
Now check the status of IMAP; if it is not enabled, then enable IMAP and Save changes.
Regards,
Willjoe