Where is option for 'Flag Flat Pass' located?

Dear all.
I want to export 2 version, graded and ungraded version.
I use : Export Page -> Advance Setting -> Enable Flat Pass -> With clip setting.
I want specific of clip only, so i choose 'with clip setting'.
I see on Documentation, for doing this, i should flag the clip :
Unfortunately, i can not find an option to flag my clips.
So, where is it located?
Thanks.
I want to export 2 version, graded and ungraded version.
I use : Export Page -> Advance Setting -> Enable Flat Pass -> With clip setting.
I want specific of clip only, so i choose 'with clip setting'.
I see on Documentation, for doing this, i should flag the clip :
Unfortunately, i can not find an option to flag my clips.
So, where is it located?
Thanks.