Archive Old Outlook Emails Remotely

My Outlook inbox has finally hit its storage ceiling. I’m on a Windows PC with the full Microsoft Outlook client installed, and the bulk of the space is taken by messages dated 2017-18 and earlier. I’d like those older emails archived safely to a local PST so my online mailbox is clear again... (Budget: $30 - $250 AUD, Jobs: Data Backup, Microsoft, Microsoft Exchange, Microsoft Outlook, Technical Support, Windows Desktop)