No Airdrop option showing in macOS Finder Preferences - Catalina

I had the same problem and fixed it thanks to a phone call with Apple Support.

Before starting you should verify that:

1. Both devices are on the same Wifi Network
2. Both devices have bluetooth enabled

The solution is composed by steps below:

1. Go to System preferences
2. Users and Groups, then click on the lock to enable modify
3. Click on + (plus) button
4. From the dropdown menù choose "Administrator"
5. Choose a "full name", for example "test"
6. Click on "account name" field, it will autofill with the same value of previous step
7. Choose a password, for example "1234" (we will delete this account at the end of the guide, so do not worry about security)
8. Confirm the password
9. Reboot your Mac
10. On login screen, choose the account created at step 5 (in this case "test")
11. Insert the password
12. Try to send a file from iPhone/iPad to the Mac and viceversa
13. Now you can reboot the Mac
14. Go to Users and Groups
15. Delete the "test" account, remember to choose "Delete the home folder"

Now you should be able to send all your photos and files to your Mac!

I just remembered a step that I didn’t described before.

once you login into your new “test” account, you should login to you iCloud account in the system preferences!

maybe that’s the point of all steps before, sorry if I remembered it just now.

You need to login to your iCloud after the step 11, and before the step 12.

Then on the step 12 you will see on your iPhone/iPad screen 2 MacBooks with the same name, you should select the one on the far right.

Turn on both Bluetooth & WIFI (they are both needed for Airdrop to function). Try to Airdrop something to your Mac. Does Airdrop work? If it works, does it now show up in the Finder?