If you find the iTunes software, it is the player that comes with Apple.

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 files to library", or drag the music directly to a blank space in the music library.

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

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

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

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

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

The video to be synchronized to the iPhone must be in mp4 format.

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

Click "Video" on the menu bar to enter the video settings interface. If "Sync Videos" is checked, click "Sync" in the lower right corner.

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