IssueTracker

Summary:
There is no way to find any documents for us to use GA4 measurement protocol to send country/device parameters in an event which can be used in report as predefined dimensions.

Expected Behavior:
Google should have a guide for user to better understand how to use GA4 measurement protocol to collect the dimensions (country/city, etc.) in the report api.

Steps to Reproduce:
Below curl command is a try to send country, device info, but they are treated as custom dimensions, not the one report used as predefined dimensions, and therefore no value can be viewed in the Reports charts.

curl -X POST 'https://www.google-analytics.com/mp/collect?measurement_id=G-VCGXCRJVNY&api_secret=g9iZ0WwEQ_qVyyLArVXDSg' \
-H 'Content-Type: application/json' \
--data-raw '{
    "client_id": "31039b79-1a05-49d7-b876-3b884d0f933d",
    "non_personalized_ads": true,
    "events": [
        {
            "name": "mepsdk2",
            "params": {
                "method": "iptest",
                "cid": "51009b79-1a05-49d7-b876-2b884d0f825c",
                "uip": "202.116.50.22",
                "country": "United States",
                "city": "Austin",
                "device_category": "Mobile"
            }
        }
    ],
    "user_properties": {
        "country": {
            "value": "United States"
        },
        "city": {
            "value": "Austin"
        },
        "device_category": {
            "value": "Mobile"
        }
    }
}'