@Margaret Adair Wotton
The location of the "Death" details/record is:
Select the "Edit" in 'Blue' on the 'left', just after "Sources'.
That will bring up a "Pop-Up" (aka "Modal) 'Window', "Edit Death".
Where you can add a 'Date' and 'Place', of "Death".
Here is a "Knowledge Article" in 'FamilySearch':
How do I change vital information in Family Tree?
I hope this helps.
If you are referring to a Member of the church who has died, the ward clerk for the member needs to mark his Membership record deceased before it will appear in Family Search. If you have your own copy of him/her, mark your living person as deceased. After both the church record and your personal record are marked deceased then you can merge them.
Thank you Brett, this answers my question
Thank you Cindy, The person was an already deceased person. Brett gave me the answer. 😊
@FamilySearch Family Tree