Currently, upgrading to QuickBooks Online Plus through Apple is not available?

Hello there, stt931.

The limited options you're seeing might be due to a temporary issue. In this case, I would recommend reaching out to Apple support directly for assistance. They can provide further assistance in upgrading your subscription. 

If you have QuickBooks concerns, such as setting up advanced reporting, online banking, managing reconciliation, transactions, importing and exporting data lists, etc., you can visit our Help articles page.

Feel free to post again if you have further questions. I'm here to assist you at all times.