Airdrop seems to be missing on my Macbook Pro System:
MacBook Pro (15-inch, 2017)
macOS 10.13.6 (17G14033)
Issue: I cannot send files to my MacBook Pro from my iPhones using Airdrop. When I try to share a file from a iPhone to the Mac using AirDrop, the Mac just doesn't show up among the available users. I looked for AirDrop among the Finder Favorites, and it's not there:

Following the instructions on this website, I navigated to the Go menu in Finder, selected Go to Folder and pasted in this path:
/System/Library/CoreServices/Finder.app/Contents/Applications 

This is what I see:

However, if I click on the AirDrop icon, I get this error message:

What is happening? Can you help me get AirDrop to work on my Mac?
EDIT: there's no AirDrop item in the Finder → Go menu

the Shift+⌘+R shortcut doesn't seem to do anything at all, and finally both WiFi and BlueTooth are turned on:
Is there any personal information in the contents of the app AirDrop? I did some digging in the package contents but couldn't find any. If it has no personal information, I can upload and attach the airdrop app, and you can save a backup of the corrupt app and paste my app in.