nx/packages/esbuild/docs/configuration-examples.md

nx g @nx/esbuild:configuration my-package

{% callout type="note" title="Overwriting existing build option" %} The configuration generator validates that an existing build target isn't already defined for the project. If you are adding esbuild to a project with an existing build target, pass the --skipValidation option. {% /callout %}

You may also provide a custom main entry file, or a custom tsconfig file if the defaults don't work. By default, the generator will look for a main file matching src/index.ts or src/main.ts, and a tsconfig file matching tsconfig.app.json or tsconfig.lib.json.

nx g @nx/esbuild:configuration my-package \
--main=packages/my-package/src/entry.ts \
--tsConfig=packages/my-package/tsconfig.custom.json