How to Do .where(field contains xyz) on Client Side

So if I have an array I have read from a server connect such as this:

message_templates.data.message_templates
   id
   message_topic

I know I can filter by a specific value of message_topic:

message_templates.data.message_templates.where(`message_topic`, 'Apple', "==")

But how would I filter it to find all items where message_topic contains the text ‘Apple’?