My Office 11 is not working. it was one time purchase

Office 2011 does not work on MacOS 10.15 Catalina. You need to purchase Office 2019 or subscribe to Microsoft 365.

I have the same issue on my late 2013 version iMac, with Office for Mac 2011 loaded. This no longer works after the latest os upgrade to Catalina.

I understand I have to now purchase a new version of office (e.g. Microsoft Home and Student 2019), but Do I have to uninstall the old version first.,before loading the new version on to my Mac?