How to work with clips with different aspect ratios in DaVinci Resolve?

Question

Video processing

The project has a video shot in FullHD format with an aspect ratio of 16:9 and a couple of clips collected frame by frame from time-lapse photos, they have an aspect ratio of 1:1 and a resolution of 2736:2736. If, when rendering, I choose the video format 1920:1080, I get black fields on all four sides of the videos in 16:9 format and black fields on top and bottom of the videos in 1:1 format
Where to set up what was originally shot in 16:9 format and render , and other formats had margins on the side (4:3, 1:1) or on top (16:10) ?

Answer 1

Project settings -> Timeline resolution.