How to collect cloudflare zero trust log with API in free plan

Hello, we are testing to introduce Cloudflare VPN.

I am satisfied in all aspects, but it is disappointing that the degree of freedom in log collection seems to be reduced.
(I know that if i use the enterprise plan, can store logs using the logpush and logpull features)

While researching other methods, I found that there was a way to check logs through the API, although it was not indicated in the official API document.

API URL that retrieves logs through login session authentication on the dashboard
(https://dash.cloudflare.com/api/v4/accounts/{identity}/gateway-analytics/activities/l4)

API URL that retrieves logs using API Key
(https://api.cloudflare.com/client/v4/accounts/{identity}/gateway-analytics/activities/l4)

In the case of the dashboard API response, all information is sufficient, but because session information is required, it is unsuitable for an automated log collection system.

And, in the log information retrieved through api.cloudflare.com, information such as user_id, device_id, and source_ip are identified as empty strings.

As a result, I am wondering if there is a way to directly collect logs with all the information using the API.
I would like to directly compensate for the only drawback of the free plan by implementing a log collection program.

thank you

(Log example from api.cloudflare.com)

{
  "result": {
    "time": 1699429412,
    "logs": [
      {
        "session_id": "{my-session-id}",
        "datetime": 1699429333,
        "account_id": "{my-account-id}",
        "user_id": "",
        "device_id": "",
        "virtual_network_id": "{my-vn-id}",
        "rule_id": "",
        "action": 4,
        "action_name": "allow",
        "source_ip": "",
        "source_internal_ip": "",
        "source_port": 62494,
        "destination_ip": "**.**.**.**",
        "destination_port": 443,
        "override_ip": "::",
        "override_port": 0,
        "transport": "tcp",
        "email": "",
        "sni": "****.****.***",
        "last_authenticated_at": 0,
        "src_country": "**",
        "dst_country": "**",
        "proxy_endpoint": "",
        "detected_protocol": ""
      }
    ]
  },
  "success": true,
  "errors": [],
  "messages": []
}