Sorry for the delay in response to your query.
As per the issue description, you want to know how to install the Adobe Export PDF pack in iMac, Is that correct ?
The records shows that you have an active subscription of Adobe Export PDF, Annuel under your Adobe ID.
Adobe Export PDF is an online Adobe Document Cloud service and it's not an application.
You can install the Adobe Reader DC in your iMac and can use the services. Download Reader from PDF reader, PDF viewer | Adobe Acrobat Reader DC
Sign in with your Adobe ID and password in Acrobat Reader and you can easily turn PDF files into editable Word, Excel, PowerPoint, and RTF (Rich Text Format) documents.
You may also refer to the link: https://helpx.adobe.com/document-cloud/help/using-exportpdf.html
Please feel free to update this discussion in case you need further assistance, etc.