Video background:

Right-click the timeline and choose Freeze Frame to easily turn a frame of the video into a still image.

The frame at the selected time point will be added as a 3-second background image scene and inserted between the two video scenes. This frame image will also be saved to the Media section with a random name.

Video layer:

Open the Timeline panel, right-click the video layer, and choose Freeze Frame.

The frame at the selected time point will be added as a 3-second image layer and inserted between the two video layers. This frame image will also be saved to the Media section with a random name.