Downloading Slicer on Mac

I am trying to download Slicer 4.11.20200930 on my MacBook Air, but I am encountering this pop-up provided on the image I uploaded. I downloaded Slicer on my iMac 2015 with ease; however, I am having complications on my air. Can you please provide recommendations and suggestions? Thank you.

See installation instructions here: https://slicer.readthedocs.io/en/latest/user_guide/getting_started.html#mac