resolve! official document is ok. but not setp by step for beginner.
- copy
project directory/mode_modules/strapi-plugin-content-manager/admin/src/components
to
project directory/extensions/admin/src/components - in cmd run
strapi develop --watch-admin - edit files in project directory/extensions/admin/src/components you can see changes
- this article has another example:
how to customize content manager UI? · Strapi