I am getting this error:

```
Cannot decode into a value of type com.blah.rest.model.UserProfile, 
because no EntityDecoder[cats.effect.IO, com.blah.rest.model.UserProfile] 
instance could be found.

```

for the following case class:

```
case class UserProfile(id: Option[Int], firstName: String, lastName: String)

```

Encountered the error on `POST` code:

```
case req @ POST -> Root / "v1" / "profiles" =>
  req.as[UserProfile] flatMap {(up: UserProfile) =>
    Ok(service.createProfile(up).asJson)
  }

```

With the following `POST` body:

```
{
   "firstName": "Jack",
   "lastName": "Appleseed"
}

```

I think this happens when the body is being converted to `UserProfile` in `req.as[UserProfile]`!

But, this is a plain vanilla case class, the `EntityDecoder` should be auto-derived! I know `akka-http` does it!

Any ideas/suggestions?

Please Note: `Http4sVersion = "0.18.0-M4"` and `circe version "0.9.0-M1"`