Hi!
You can create a custom controller on your content type to validate whenever a request isAuthenticated and a post requires authentication.
Something like this:
async validateAuthenticatedPost(ctx){
await this.validateQuery(ctx);
const { user } = ctx.state
const { id } = ctx.params
const article = await strapi.entityService.findOne('api::article.article', id)
if(article.requiresAuth !== user.id){
throw strapi.errors.forbidden()
}
}
This is just an example, you will have to adapt it to your needs, but basically you will only return the authenticated post if there is an authenticated user