Extending public runtime config type

I have a

featureFlags

featureFlags

featureFlags

featureFlags property on my

runtimeConfig.public

runtimeConfig.public

runtimeConfig.public

runtimeConfig.public config. However, when I try to do something like:

const { featureFlags: runtimeFeatureFlags = '' } = useRuntimeConfig().public;
const featureFlags = ref(runtimeFeatureFlags.split(','));

const { featureFlags: runtimeFeatureFlags = '' } = useRuntimeConfig().public;
const featureFlags = ref(runtimeFeatureFlags.split(','));

const { featureFlags: runtimeFeatureFlags = '' } = useRuntimeConfig().public;
const featureFlags = ref(runtimeFeatureFlags.split(','));

const { featureFlags: runtimeFeatureFlags = '' } = useRuntimeConfig().public;
const featureFlags = ref(runtimeFeatureFlags.split(','));

The

featureFlags

featureFlags

featureFlags

featureFlags property type is

unknown

unknown

unknown

unknown.
I tried adding this to

<srcDir>/index.d.ts

<srcDir>/index.d.ts

<srcDir>/index.d.ts

<srcDir>/index.d.ts:

declare module 'nuxt/schema' {
  interface PublicRuntimeConfig {
    featureFlags: string;
  }
}
export {};

declare module 'nuxt/schema' {
  interface PublicRuntimeConfig {
    featureFlags: string;
  }
}
export {};

declare module 'nuxt/schema' {
  interface PublicRuntimeConfig {
    featureFlags: string;
  }
}
export {};

declare module 'nuxt/schema' {
  interface PublicRuntimeConfig {
    featureFlags: string;
  }
}
export {};

Still same error. I am an app extending from a layer if that makes any difference. Where am I going wrong here?