Try MacArmy Mac PST Converter that has a simple GUI interface to directly import PST files to desired saving option formats like MBOX, HTML, Gmail, EML, Office 365, Office 365, etc. There is no need to install the Outlook editions for the conversion. It gives the dual options like Select File(s)/Folder(s) to simply load the PST files. It works on all Mac OS editions i.e. Monterey, High Siera, Catalina, Big Sur, Mojave and many more. It provides the free demo version that helps to enhance the conversion skills and permits to convert 25 PST files for free.