how do i transfer music to my iphone from itunes on my computer

• Mac Book Air Retina 13" macOS Catalina 10.15.1
• iPhone SE with iOS 13.3 :- Does not use iCloud Library
• iPhone 6 with iOS 12.4.4 :- use iCloud Music Library

This is two a Step Process (To sync music from this computer, turn off Cloud Music Library)

1. Apple Music: Import music (MP3) to Apple Music Library on Mac
2. Finder: Sync between Apple Music on Mac and iPhone

Watch the GIF for complete process

To sync music from this computer, turn off Cloud Music Library.

Watch the same GIF as a QT movie file uploaded by me on YouTube:- Transfer MP3 Music from Mac (Catalina) to iPhone (iOS13.3)