How to call different api resource from paging source or remote mediator Kotlin

Hey I want to call two different api for my Paging Library 3. I want to ask what is best suit for me to use Paging Source or Remote Mediator?. What is the use case of both? Can someone please explain me.

For 1st api call only for single time

@GET("/movie?min=20")

Above api call returns this response

data class movie(
  var id: Int?,
  var name: String?,
  var items : List<Genre>?
}

Now for 2nd api call its loop to call again and again

@GET("/movie?count=20&&before={time}")

Above api call retrun this

data class movie(
  var items : List<Genre>?
}

Genre

data class Genre(
   var type: String?,
   var date: String?,
   var cast: String?
}

Genre have data in both api call. I tried to google this and found this Example. But inside this both api return same data. But in my case both returns little bit different. Also id, name is only used in UI component else list will go to adapter. But I didn't understand how to achieved this. I am new in Flow, it too difficult to understand, to be honest I am trying to learning CodeLab. Another important thing when 1st time api call, in which the last item contains date will send to 2nd api call in time parameter and then 2nd api last item date call again 2nd api, this will go in loop. So how can I track this again in loop condition. Third I want to update data at top of list, can we store data in memory than we can update value on that list? Thanks for advance. Sorry for my wrong english.

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