Add Smart Lock screen security options to Amazon Fire HD 8? Smart Lock is present in vanilla Lollipop 5.* but isn't included in Amazon Fire HD 8, which is based on Lollipop.

Can Smart Lock be added/enabled on Amazon Fire HD 8 tablet devices?
Only a few devices support Smart Lock(mainly Motorola and Samsung)

If you are having trouble finding Smart Lock, try


Go to Settings > Security > Screen lock > Set the Pin Lock
After setting the Pin Lock go back to the Security Menu, at the Bottom of 
security menu you will find Trust Agent
Go to Settings > Security > Trust Agent
Enable Smart lock ( Google )
Select Smart Lock