@prince69 The issue is you’re extending the wrong class. You’re using your ResourceCollection class as if it were a single resource class.
So, extend just the regular Resource class instead of ResourceCollection, and rename your resource to what it is: UserResource. Your files should then look like this:
return UserResource::collection(User::all());
class UserResource extends Resource
{
public function toArray($request)
{
return [
'first_name' => $this->first_name,
'last_name' => $this->last_name,
'email' => $this->email,
date_of_birth' => $this->date_of_birth->toDateString(),
];
}
}