just updated to Mojave. cannot sync new iphone X to itunes - error message I need version 10.13.99 or older

I bought a new iPhone X today. I tried to sync with iTunes and was informed I need to upgrade to Mojave. After install, I plugged my new phone in and got the message that iTunes will not sync as I need a version 10.13.99 or older (I'm guessing Mojave is version 10.14 and now incompatible with iTunes). Help! This is an absolute nightmare!!!!