Open CapCut and start a new project or open an existing one
Tap Add or the plus icon to import your video
Tap Audio at the bottom of the screen
Choose Sounds, Extracted, or From device
Select a music track from CapCut’s library or your device
Tap the plus icon or Add to place the music on the timeline
Trim the music by dragging the edges of the audio clip
Move the audio clip to sync it with your video
Adjust the volume if needed
Tap Export to save the edited video