No 'sync music' check box & all music still not transferred to my iPhone even after the ICloud library applied and no way to tell me how to add the rest.

I connect my iPhone to my laptop via USB, the device appears in my iTunes, I click on it, then click on the music settings tab, but there's no 'sync music' box on that screen. At the top of the menu is a message informing me "iCloud Music Library is On" and that's about it. I've included a screen grab at the bottom of this post.

In past editions of iTunes, the said missing 'sync music' feature has allowed me to sync particular playlists to my phone, as opposed to my entire music library. And its omission seems especially odd because there are 'sync movies', 'sync podcasts', etc options when I click on those respective tabs. Is it a glitch in my iTunes or is there a specific step I have to follow to have access to this option? Thanks.