Wrong mapping fields names for webtracking with ElasticSearch

In the doc (https://www.app-metrics.io/reporting/reporters/elasticsearch/) it is recommended to create an index and to send the mapping :

Add an index and the document mappings to Elasticsearch using the default mappings provided in the github repository

But when i send this command to ES :

PUT appmetricssandbox/_mapping/timer?update_all_types
{
  "properties": {
    "tags.env": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.exception": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.app": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.route": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.server": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.item": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.client_id": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.http_status_code": { 
      "type":     "text",
      "fielddata": true
    },
    "tags.health_check_name": { 
      "type":     "text",
      "fielddata": true
    }
  }
}

I get this error for ES :

{
"error": {
"root_cause": [
{
"type": "mapper_parsing_exception",
"reason": "Field name [tags.env] cannot contain '.'"
}
],
"type": "mapper_parsing_exception",
"reason": "Field name [tags.env] cannot contain '.'"
},
"status": 400
}

[alhardy]

The ES reporter has fallen behind since breaking changes in ES were introduced.

I'm struggling to maintain all reporters on my own outside the those I use myself in production.

Any help appreciated.