Too old apparently!?
System requirements for Continuity on Mac, iPhone, iPad, iPod touch, and Apple Watch
Here's what you need to use Auto Unlock, Continuity Camera, Handoff, Instant Hotspot, iPhone Cellular Calls, SMS/MMS messaging, Universal Clipboard, Continuity Sketch, and Continuity Markup...
Handoff
Handoff works with these devices and operating systems:
iOS 8 or later OS X Yosemite or later watchOS 1.0 or later
iPhone 5 or newer
iPad Pro (all models)
iPad (4th generation) or newer
iPad Air or newer
iPad mini or newer
iPod touch (5th generation) or newer
MacBook introduced in 2015 or later
MacBook Pro introduced in 2012 or later
MacBook Air introduced in 2012 later
Mac mini introduced in 2012 or later
iMac introduced in 2012 or later
iMac Pro (all models)
Mac Pro introduced in 2013 or later
Apple Watch (1st generation)
Apple Watch Series 1
Apple Watch Series 2
Apple Watch Series 3
Apple Watch Series 4
Apple Watch Series 5
https://support.apple.com/en-us/HT204689