Missing fuse cause of no A/C?

2011 Hyundai Accent

I don’t know much about cars, so I’d like someone to tell me if this missing fuse could be causing the AC to not activate. It’s already been to a mechanic, so I assume they checked, but I’d like a second opinion.

Then according to this link A/CON #2 (the missing fuse) is for the A/C Control Module and the fuse next to it (currently there) is for the A/Con Relay. Once I saw that I decided I’d try to use the horn fuse, which is the correct size, but the fuse was loose when I put it in the A/CON #2 slot. That’s when I noticed the metal connector that the horn slot has was not present for the A/CON #2 slot. Some of the other slots are empty as well, so I’m wondering if this one was always missing or if the metal connector may have been damaged when someone tried changing the fuse. If this fuse, and it’s connector, are supposed to be there for the AC how difficult would it be to fix? And if this needs to be done by a mechanic what would be a reasonable price?

Thank you for any help.