Merge Field Creation

In a Pages letter, I want to add a merge field. My objective is to drag a Contacts group into the letter and have the Dear {merge field} populate. I tried Help to no avail and the User's Manual says

If the Link inspector isn’t open, choose Insert > Sender Field or Insert > Merge Field.

I can't find the Link inspector, or cause it to open, and the dropdown menu from Insert doesn't have Sender Field or Merge Field. What to do? Pages version 5.1 (1769) Thanks