ElasticPress returns recent posts instead of related posts

I have the following environment up and running:

Windows 10, XAMPP, WordPress Site, ElasticSearch.
ElasticSearch is working correctly in http://localhost:9200/.
I installed the plugin ElasticPress, configured it and indexed all my posts.
I tried the widget “Related Articles” of ElasticPress, but it always returns the recent posts.

> Here’s the copied CURL command:

curl -XPOST -H 'Content-Type: application/json' -d '{"from":0,"size":5,"sort":[{"post_date":{"order":"desc"}}],"query":{"more_like_this":{"like":{"_id":102},"fields":["post_title","post_content","terms.post_tag.name"],"min_term_freq":1,"max_query_terms":12,"min_doc_freq":1}},"post_filter":{"bool":{"must":[{"terms":{"post_type.raw":["post"]}},{"terms":{"post_status":["publish"]}}]}}}' 'http://localhost:9200/mywebsite-post-1/_search'

> Query Response Code: HTTP 200

> Here’s a simplified Query Result:

{
    "took": 33,
    "timed_out": false,
    "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 26,
            "relation": "eq"
        },
        "max_score": null,
        "hits": [
            {
                "_index": "mywebsite-post-1",
                "_type": "_doc",
                "_id": "132",
                "_score": null,
                "_source": {
                    "post_id": 132,
                    "ID": 132,
                    ... other fields related to the current hit.
                },
                "sort": [
                    1592590310000
                ]
            },
            {
                "_index": "mywebsite-post-1",
                "_type": "_doc",
                "_id": "133",
                "_score": null,
                "_source": {
                    "post_id": 133,
                    "ID": 133,
                    ... other fields related to the current hit.
                },
                "sort": [
                    1592590168000
                ]
            },

            ... other hits
        ]
    }
}

I don’t know how to instruct ElastiPress to sort by relevancy in order to have related posts.`