How to search by news headlines text

My code is as follows :

import eikon as ek

headlines = ek.get_news_headlines(query='IBM.N', count=1, date_from=None, date_to=None,
                                  raw_output=True, debug=False)
print(headlines)

Running result is as follows :

{'headlines': [{'displayDirection': 'LeftToRight', 'documentType': 'Story', 'firstCreated': '2024-11-07T08:55:01.000Z', 'isAlert': False, 'language': 'L:en', 'reportCode': '', 'sourceCode': 'NS:ZAWYA', 'sourceName': 'Zawya', 'storyId': 'urn:newsml:newswire.refinitiv.com:20241107:nZawJWcL:1', 'text': 'PRESSR: DMCC AI Centre collaborates with IBM Consulting to expand key AI services offering', 'versionCreated': '2024-11-07T08:55:01.000Z'}], 'newer': '/headlines?payload=ey.......'}

My Question is as follows:

What value should be assigned to the parameter 'query' in the get_news_headlines method to query news filtered by keyword based on the keyword of the headline (i.e., the keyword in the returned 'text' property value, such as 'AI Centre') ?