Introduce the operation method:
First, the new horizontal screen resolution.
Open the love clip on the computer, and change the video size to1920 *1080 (1080p) in the new box that pops up.
And import the vertical video into the "Video" panel of the software.
Second, add a background picture.
Double-click the video preview area on the right side of the superimposed material-Add Map panel, and click Add Map to List in the lower left corner of the pop-up box to import personal pictures.
Resize and position the picture to cover the black edges on both sides of the video.
I hope I can help you!