Thank you for your post.
First, temporarily disable the Send Mail script step. Then, run the script. Close the file and return to the home screen and ensure a "Backup iOS.pdf" file is created. If not, then try using Get (DocumentsPath) instead of Get (Temporary Path). That is,
Set Variable [ $Output ; Value: Get (Documents Path) & "Backup iOS.pdf"]
Once you verify the PDF file is created, then enable the Send Mail script step, and make sure the attachment is set to "$Output" only. It looks like you are trying to add "file"$Output"". This is incorrect.
Let me know if you continue to run into difficulty.
You are a STAR!!