FIeld configuration schemes are not available if you are actually using a next gen project in Jira cloud. In case you are using a classic project you can assign the field configuration scheme to a project like it is outlined in the article which link Carlos posted above.
Probably you are looking for Screens (organised in Screen Schemes) instead?
The documentation is to be found here:
...ollected feedback from users around the lack of shortcuts, and we’re here to address that: In next-gen projects, I miss the keyboard shortcuts badly. This is particularly true on the Board, but also i...
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