I've found decision by adding many elements to "operations=[ad_group_criterion_operation]" list. It's working correctly. Thank you for attention!
        # Create keyword.
        ad_group_criterion_operations = []
        for keyword_text in keyword_texts:
            ad_group_criterion_operation = client.get_type("AdGroupCriterionOperation")
            ad_group_criterion = ad_group_criterion_operation.create
            ad_group_criterion.ad_group = ad_group_service.ad_group_path(
                customer_id, ad_group_id
            )
            ad_group_criterion.status = client.enums.AdGroupCriterionStatusEnum.ENABLED
            ad_group_criterion.keyword.text = keyword_text
            ad_group_criterion.keyword.match_type = (
                client.enums.KeywordMatchTypeEnum.BROAD  # EXACT, PHRASE, BROAD
            )
            ad_group_criterion_operations.append(ad_group_criterion_operation)
        # Optional field
        # All fields can be referenced from the protos directly.
        # The protos are located in subdirectories under:
        # 
https://github.com/googleapis/googleapis/tree/master/google/ads/googleads        # ad_group_criterion.negative = True
        # Optional repeated field
        # ad_group_criterion.final_urls.append('
https://www.example.com')
        # Add keyword
        ad_group_criterion_response = (
            ad_group_criterion_service.mutate_ad_group_criteria(
                customer_id=customer_id,
                operations=ad_group_criterion_operations,
            )
        )