separatorsToIndex property
Control which non-alphanumeric characters are indexed.  By default, Algolia ignores non-alphanumeric characters like hyphen (-), plus (+), and parentheses ((,)). To include such characters, define them with separatorsToIndex.  Separators are all non-letter characters except spaces and currency characters, such as $€£¥.  With separatorsToIndex, Algolia treats separator characters as separate words. For example, in a search for "Disney+", Algolia considers "Disney" and "+" as two separate words.
Implementation
@JsonKey(name: r'separatorsToIndex')
final String? separatorsToIndex;