Hello @abconstr you should be able to go to the following site and download the latest R15 version of QB Mac 2021, it will contain the full installer and the Server application that will work with it. You just need to select the US for the country, QuickBooks Mac Desktop for the product and 2021 for the version. Hopefully this will fix your issue.
https://downloads.quickbooks.com/app/qbdt/products?src=care
