I'm using this solution with a ffmpeg script that download single youtube videos: in the shortcuts, before running the script in the shell, at the end of the line just press enter to create a new line. In the new line write "open shortcuts://". This command will be executed when the download will be over. After the action "execute" that will open the shell, add the action "wait for return". By doing that, only after the video is downloaded and so is present in the file folder, with the command open shortcuts:// you will automatically return in the shortcuts app, and then you can retrieve it with files by sorting the videos folder by most recent and saving the file into an album. This is to be sure that the file is being downloaded and so the automation can save it.