Adds a new media preview to the beginning of the list of media previews of a bot. Returns the added preview after addition is completed server-side. The total number of previews must not exceed getOption("bot_media_preview_count_max") for the given language
| bot_user_id |
Identifier of the target bot. The bot must be owned and must have the main Web App |
| language_code |
A two-letter ISO 639-1 language code for which preview is added. If empty, then the preview will be shown to all users for whose languages there are no dedicated previews. If non-empty, then there must be an official language pack of the same name, which is returned by Client.get_localization_target_info |
| content |
Content of the added preview |