2. Then in the summary interface of Apple's mobile phone, check the "Manually manage music and videos" option at the bottom, and then click the "Apply" button at the bottom right.
3. After the above operations are completed, please click on the "On this iPhone" column above, and then click the "Movie" option on the left.
4. Next, we find the video file in the computer and drag the video directly to the movie window in iTunes.
5. Then you can see a video file being updated and uploaded in the status bar window at the top middle of iTunes.
6. Finally, when we open the video on iPhone, we can see the video file just uploaded and imported from iTunes.