As per the description above, you want to download the ExportPDF on Mac computer, Is that correct?
Adobe ExportPDF is an Online Document Cloud service, and it cannot be downloaded as an application, but you can access the service through a browser or through desktop and mobile app Adobe Reader DC.
User the service through the following URL ExportPDF: https://cloud.acrobat.com/exportpdf
You may also refer to the following KB doc for more information Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud... Link: https://forums.adobe.com/docs/DOC-8841
Hope this helps, and let us know how it goes.