I got the information that "Microsoft Document Connection" needs to be updated on my MacOs. Contact the developer for more information. It's something about 32-bit app compabilities up to 64-bit. Please advise me how to get this.

32-bit apps don’t run on 10.15 Catalina or later. Microsoft Document Connection was part of Office 2011, needed for working with OneDrive and SharePoint. From Office 2016 on it was no longer needed. Office 2011 is 32-bit, so you’ll need Office 2019 or a Microsoft 365 subscription to run Office, but there’s no need for Microsoft Document Connection so you can just ignore that.