Using SQL LIKE operator in MongoDB indexes

I have a Flask app that queries my self-managed MongoDB.

I've created an index on two fields so that I can perform a text search on it.

The search is working fine, but it is only matching full words.

For example, for the phrase "i am halfminded", if I perform a search with the keyword halfminded it works but doesn't work for half.

This is what i am using:

    def get_paginated_data(self, page, query):
    skip = (page - 1) * self.PER_PAGE
    data = (
        self.collection.find({"$text": {"$search": query}})
        .skip(skip)
        .limit(self.PER_PAGE)
    )
    return list(data)

I have tried using the below code as well:

def get_paginated_data(self, page, query):
    skip = (page - 1) * self.PER_PAGE
    data = (
        self.collection.find({"$text": {"$regex": f"/.*{query}/"}})
        .skip(skip)
        .limit(self.PER_PAGE)
    )
    return list(data)

but this throws the following error:

pymongo.errors.OperationFailure: Missing expected field "$search"

Can anyone advise on how i can get the partial text search to work.