I dont see the add context and description button as shown in documentation?

[Nauman Ahmed]

I want to set context for system field, however the option to set context seems to be hidden / unavailable

Jira Core 8.20.7, License type commercial (Data Centre)

This is my instance view

This is the view mentioned in documentation

Configuring contexts and default values for the Description field | Administering Jira applications Data Center and Server 9.2 | Atlassian Documentation

[John Funk · Accepted solution]

Hi Nauman,

As the note at the top of your first image says, only some system fields can be set. In reality there are very few, and I don't even know of one off the top of my head. 

Bottom line though is that you should not try to change the context of a system field. 

[John Funk]

One other note - some fields like Priority and Resolution can be hidden from the Create and Edit screens, but that's about the only configuring you can do.