Serializer for class 'MultipartBody' is not found

Hi I am trying to make multiform request with ktor but I am getting above error. How can I serilize MultiPartBody?

   val body = MultipartBody.Builder().setType(MultipartBody.FORM)
    .addFormDataPart("choice","John Wick")
    .addFormDataPart("image",path,
        File(path).asRequestBody("application/octet-stream".toMediaType()))
    .build()

val httpResponse = client.post {
    url("https://example.com")
    setBody(body)
    header("Content-Type","application/json")
    header("Authorization", "Bearer key")
}

Ktor cannot send directly an object of the okhttp3.MultipartBody class. Please use the MultiPartFormDataContent class instead:

val body = MultiPartFormDataContent(
    formData {
        append("choice", "John Wick")
        append("image", File(path).readBytes(), Headers.build {
            append(HttpHeaders.ContentType, "application/octet-stream")
            append(HttpHeaders.ContentDisposition, "filename=\"file\"")
        })
    }
)