Hello
Probably a bit late, but I also ran into little documentation / examples.

Here is something that works for me :

...
@googleViewId "ga:XXXXXX"

def google_analytics_authenticate() do
    {:ok, google_bearer_token} = Goth.fetch(YourAppName.Goth)
    google_bearer_token.token
end

def google_analytics_query() do
    conn =
      authenticate()
      |> GoogleApi.AnalyticsReporting.V4.Connection.new()

    {:ok, %Model.GetReportsResponse{reports: [%Model.Report{} = resp]}} =
      conn
      |> Reports.analyticsreporting_reports_batch_get(
        body: %Model.GetReportsRequest{
          reportRequests: [
            %Model.ReportRequest{
              viewId: @googleViewId,
              dateRanges: [
                %Model.DateRange{
                  startDate: "2021-10-05",
                  endDate: "2021-10-22"
                }
              ],
              dimensions: [
                %Model.Dimension{
                  name: "ga:browser"
                },
                %Model.Dimension{
                  name: "ga:sessionDurationBucket"
                }
              ],
              metrics: [%Model.Metric{expression: "ga:users"}]
            }
          ]
        }
      )
    resp
end