How to disable auto-mount on desktop?

I've just purchased several used 2nd SD Card and I've always been careful with foreign storage media for fear of virus, malware, etc.

How do i plug the sdcard without steamdeck auto mounting it? I want to format/shred everything without the possibility of executing whatever is inside it

i fear dolphin file manager automatically opened/redirected to the file location when the device is plugged in and it somehow triggered a malware?