In SU versions previous to 2020 there was an extension that allowed automating a laout file with one page for each SU scene. The extension does not appear to be available for SU 2020. Is there another way to do this quickly w/o creating Layout pages one at a time?
I think that “Create LayOut File” may be the extension you are thinking of? It isn’t marked as being compatible with SketchUp 2020 but I just tried it and it seems to work ok, maybe the compatibility just hasn’t been updated. Install from the SketchUp Extension Warehouse and it appears in the Extensions menu.
Side note: Whichever scene I had active when I used the extension became Page 1 in the LayOut file, I don’t know if that’s normal. To get the desired resulting pages, be sure to have your first scene active and Save it in that state before you use the extension. That got the intended result for me.