How to add dateModified Custom Schema to single post

Hi,

I would like to insert, with the help of Custom Schema field, available at the end of each post, the dateModified attribute.

I want to let Google crawl know when a post was last updated. What I’m actually looking for is a way to make Google display last modified date in search results instead of the published date.

This will attract more users to click on the search result, as readers are tempted to click on more recent articles displaying in Google Search.

For example I have a post that was initially published on:
Published on: Dec 9, 2018 at 17:59
and updated:
Updated on: Jul 9, 2020 @ 17:34

How can I manually insert the updated data in the Custom Schema field?
Is there a line of code that you can provide?

I notice that the current source code displays the following meta, but apparently Google still displays the published time in search results instead of modified time.

Any idea why?
<meta property=”article:published_time” content=”2018-12-09T17:59:06-05:00″>
<meta property=”article:modified_time” content=”2020-07-09T17:34:43-04:00″>
<meta property=”og:updated_time” content=”2020-07-09T17:34:43-04:00″>

Many thanks in advance.

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