How to Sync Individual Songs to iPhone with Apple Music on M3 Macbook Air

I recently bought a M3 Macbook Air with Sonoma pre installed. I used to have a very old MacBook Pro (2007) with the last allowed OS X El Capitan. I had iTunes 12.8.2.3 running, I only used it with my iPhone for my downloaded files of mp3 or aac, never had Apple Music subscription. I had playlists and smart playlist but I also had the option of dragging individual songs onto my iPhone.

Now with Apple Music, I can still drag individual songs to my iPhone but within the sync settings, then music, I choose playlist and scroll down to the bottom, there is no list of all the individual songs that I dragged over to my iPhone, it shows me all the checked smart playlist or playlist that I have synced to the iPhone but totally nothing about the manually added songs that was available on my old iTunes. I’ve asked Apple tech but they weren’t even aware that it was ever available in the first version of Apple Music! Does anyone have an idea where I can locate this option on Apple Music or has it been intentionally removed?

[Re-Titled by Moderator]