{'size': 5, 
       'query': {
               'bool': {
                    'must': [
                          {'knn': {'page_content_embedding': {'vector': [-0.03517193719744682, 0.0035374287981539965, 0.012508848682045937, -0.011280038394033909, -0.028579039499163628, 0.031669460237026215, -0.018866287544369698, -0.02781379222869873, -0.045738235116004944,......], 
                           'k': 5}
                            }
                           }
                           ], 
                     'filter': {'match_phrase': {'credit_cards': 'Product One'}}}}}

Why does this say
opensearchpy.exceptions.RequestError: RequestError(400, ‘parsing_exception’, ‘[size] query malformed, no start_object after query name’)

Opensearch dashboard says there are 245 hits for

{
  "query": {
    "match_phrase": {
      "credit_cards": "Product One"
    }
  }
}