iTunes requires software update to connect to iPhone

I have a 2012 MacBook Air running Mojave 10.14.6. I updated my iPhone XS to iOS 14.3 and now I can't connect my phone to iTunes. I get a message saying I need to do a Mac software update. The only update available is not an update but an UPGRADE to Catalina. I don't want to upgrade because I am still using some 32 bit software. What can I do?