How to add mp3 to iphone music library without itunes

For Apple Music, touch and hold desired music, then tap Add to Library > Library, choose music, and select Download.
For YouTube Music, navigate to desired music and select Download.
For iCloud Drive, on Mac, open Finder > iCloud Drive > File > New Folder, name it Music, and drag music to the Music folder.

This article explains how to add music to an iPhone using Apple Music, YouTube Music, and an iCloud Drive. Instructions apply to iOS 10.0 and up, and macOS 10.10 and up.

Apple Music offers millions of tracks that can be streamed over a wireless network, but you can also save those tracks (or playlists, albums, or videos) to your iPhone to enjoy offline.

To enable this feature, turn on Library Syncing for your Apple ID. Go to Settings > Music, then turn on Sync Library.

If you want all the songs you add from Apple Music to download to your iPhone automatically, go to Settings > Music and turn on Automatic Downloads.

Open the Apple Music App on your iPhone and navigate to the song, album, playlist, or video you want to download.
Touch and hold the song, album, playlist, or video, and then tap Add to Library.
Go to your Library and tap the song, album, playlist or video you just added.
Tap the Download icon (cloud with a down arrow.)
Your song, album, playlist, or video has been downloaded and you can enjoy it on your iPhone even when offline.

If you're a YouTube Music Premium member, enjoy music offline by downloading your favorite songs, playlists, or albums to your iPhone.

Open YouTube Music and navigate to the song, album, or playlist you want to download.
Tap the Download arrow.
The song, album, or playlist is now added to the Downloads section of your Library, and you can enjoy it offline anytime.

If you have your music collection on your Mac and/or an external hard drive and are comfortable manually managing your songs, use iCloud Drive to add tracks to your iPhone.

iCloud's terms explicitly prohibit the uploading of content for which you don't have the express permission to copy or share. Saving music you don't have the correct rights to upload, even for personal listening, could lead to your iCloud account being suspended.

On your Mac, open Finder and navigate to iCloud Drive.
Select File > New Folder (or press Shift+Command+N). This creates a new untitled folder.
Name the folder "Music."
Open the Music folder.
Locate the tracks you want to access on your iPhone. Drag them across to your Music folder.

If you want to be sure the tracks remain available in their original folders, copy and paste them to your Music folder, rather than drag and drop. To do this, press Command+C to copy it from its original location, and then press Command+V to paste it into the Music folder.
Your music will automatically upload to iCloud Drive.
Once your tracks have uploaded, your music will be available via iCloud on your iPhone. To access them, open the Files app on your iPhone.
Tap iCloud Drive.
Navigate to and tap the Music folder to open it. You'll see the same tracks you uploaded via your Mac.
Tap the track you want to play and it will automatically download to your device. Alternatively, tap the cloud and arrow icon to save the track to your iPhone.
Tap any track to play it within iCloud Drive.

Your iCloud Drive files on your iPhone are mirrored to your iCloud Drive Files on your Mac. If you delete tracks on your iPhone, they're automatically deleted on your Mac, and vice versa.
Your music is now saved to your iPhone.