you are not the one to set the rating. you need to read the guidelines - this app id for +13 readers so every part of the story has to be +13 - the guidelines explain more in detail what is and what is not allowed in episode stories…so instead of thinking about rating just read the guidelines and write in accordance with it.
You can have make-out scenes with clothes.
You cant he explicit sexual intercourse or dialogue
If you are in +13 but thill wants to add an option to skip some scenes that is totally OK and is more up to you than a must. Usually, its offered for scenes that might be triggering for some readers.