Welcome to Apple Support Communities.
It's my understanding that you're missing some Airdrop settings at the bottom of the window. I may be able to help with this. What devices are you trying to use AirDrop with? Check out this article:
Use AirDrop to send content from your Mac
To send items to an iPhone, iPad, or iPod touch, or to receive items from those devices, you need a 2012 or later Mac model with OS X Yosemite or later, excluding the Mac Pro (Mid 2012).
To send items to another Mac, you need:
- MacBook Pro (Late 2008) or later, excluding the MacBook Pro (17-inch, Late 2008)
- MacBook Air (Late 2010) or later
- MacBook (Late 2008) or later, excluding the white MacBook (Late 2008)
- iMac (Early 2009) or later
- Mac Mini (Mid 2010) or later
- Mac Pro (Early 2009 with AirPort Extreme card, or Mid 2010)
Learn how to identify your model of MacBook, MacBook Pro, MacBook Air, iMac, Mac mini, or Mac Pro.
Let me know if this helps.
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