Message text of the start page; 0-getOption("business_start_page_message_length_max") characters.
Greeting sticker of the start page; pass null if none. The sticker must belong to a sticker set and must not be a custom emoji.
Title text of the start page; 0-getOption("business_start_page_title_length_max") characters.
Describes settings for a business account start page to set.