Cannot get OTPL exporter to start in ECS sidecar

[TomasMadajevas]

I am trying to get DataDog agent to work as OTPL traces (and later metrics) exporter. Service in question runs in ECS and agent is hosted as a sidecar. Its configuration:

{
      "name": "datadog-agent",
      "image": "public.ecr.aws/datadog/agent:7.68.0-linux",
      "portMappings": [],
      "environment": [
        {
          "name": "DD_APM_NON_LOCAL_TRAFFIC",
          "value": "true"
        },
        {
          "name": "DD_SITE",
          "value": "datadoghq.com"
        },
        {
          "name": "DD_PROCESS_AGENT_ENABLED",
          "value": "true"
        },
        {
          "name": "ECS_FARGATE",
          "value": "true"
        },
        {
          "name": "DD_APM_ENABLED",
          "value": "true"
        },
        {
          "name": "DD_LOGS_ENABLED",
          "value": "true"
        },
        {
          "name": "DD_OTELCOLLECTOR_ENABLED",
          "value": "true"
        },
        {
          "name": "DD_REMOTE_CONFIGURATION_ENABLED",
          "value": "false"
        }
      ],
      "mountPoints": [],
      "volumesFrom": [],
      "secrets": [
        {
          "name": "DD_API_KEY",
          "valueFrom": "***"
        }
      ]
    }

Once started it tries to access some local ports that nothing is listening on and fails:

• error fetching remote otel config: %w Get "https://localhost:7777": dial tcp 127.0.0.1:7777: connect: connection refused
• Unable to fetch fresh inventory metadata: error fetching remote otel config: %w Get "https://localhost:7777": dial tcp 127.0.0.1:7777: connect: connection refused
• unable to establish stream, will possibly retry: rpc error: code = Unavailable desc = connection error: desc = "transport: Error while dialing: dial tcp :5001: connect: connection refused"

Maybe there is something obviously wrong with my configuration? Or, maybe, there is a detailed tutorial?