I can’t find the screen you show. I went through every screen on every tab and it’s just not there, or at least I can’t see it and “search” can’t find it either.
Please provide the steps to get where I need to be.
This is what I hate about all the documentation: the screens don’t look like what I see and explanations start in the middle assuming a start point that is not provided.
Wordpress: 4.8
Theme: Artwork Lite
Installed: Woo Commerce
Plugin: Flexible Product Fields