Photography XH2S 6K Open Gate - 6240 x 4160 4K Ultra HD (16:9) - 3840 x 2160 4K Ultra HD (4:3) - 2880 x 2160 4K Ultra HD (3:2) - 3240 x 2160
Add the clips to the timeline, then under Edit > Inspector > Retime and Scaling, select Fill under the scaling setting.
John Razalo - Classic Film Frames