The URL which you provided only showed how to use the merge field expression. I want to create a merge field functionality Below are step by step image.
Step1: ---------- I want to create a button.
Step2: --------- Once i will click on button, i want the below functionality.
go to below link for your solution
https://help.salesforce.com/articleView?id=pages_merge_fields.htm&language=en_US&type=0
let me inform if it helps you
thanks
The URL which you provided only showed how to use the merge field expression.
I want to create a merge field functionality
Below are step by step image.
Step1:
----------
I want to create a button.
Step2:
---------
Once i will click on button, i want the below functionality.