Detailed operation:

Download and open the iTunes software, and connect the iphone to the computer.

Synchronize music:

Click the icon in the upper left corner and select "Add File to Library", or drag the music directly to the blank space of the music library.

After adding, click "iphone" in the upper right corner to enter "Administrator's iphone" settings.

Click "Music" on the menu bar to enter the music setting interface. If "Sync Music" is checked, click "Sync" in the lower right corner.

If it is not selected, please select Sync Music, and then click Apply in the lower right corner.

In the library, click "Music" on the menu bar, and select "Movie" in the pop-up "Library" option.

Click the icon in the upper left corner and select "Add File to Library", or drag the video directly to the blank space in the movie library.

The video to be synced to iphone must be in mp4 format.

Click "iphone" in the upper right corner to enter "Administrator's iphone" settings.

Click "Movie" on the menu bar to enter the movie setting interface. If "Sync Movie" is selected, click "Sync" in the lower right corner.

If it is not checked, check "Synchronize movies" and click "Apply" in the lower right corner.