Calling Google Local Services API from Google Sheets

I am attempting to call the Local Services API, which is documented here: Local Services API documentation

I am calling the API inside of Apps Script, which is a way to write JavaScript inside of a Google Sheet. I have closely followed the tutorial that has been written to call other Google APIs in Apps Script, but I have not been able to call this one.
Here is the function to call the API:

function makeRequest() {
  var adsService = getAdsService();
  console.log(adsService.getAccessToken()) //I am getting a token back here
  var response = UrlFetchApp.fetch('https://localservices.googleapis.com/v1/accountReports:search?query=manager_customer_id:{manager_customer_id}', {
    headers: {
      Authorization: 'Bearer ' + adsService.getAccessToken()
    }
  });}

The makeRequest() function calls the getAdsService function below. Inside of getAdsService I am specifying ‘adwords’ and I have set the scope for .setScope('https://www.googleapis.com/auth/adwords')

function getAdsService() {
  // Create a new service with the given name. The name will be used when
  // persisting the authorized token, so ensure it is unique within the
  // scope of the property store.
  return OAuth2.createService('adwords')
      // Set the endpoint URLs, which are the same for all Google services.
      .setAuthorizationBaseUrl('https://accounts.google.com/o/oauth2/auth')
      .setTokenUrl('https://accounts.google.com/o/oauth2/token')

      // Set the client ID and secret, from the Google Developers Console.
      .setClientId(ClientID)
      .setClientSecret(ClientSecret)

      // Set the name of the callback function in the script referenced
      // above that should be invoked to complete the OAuth flow.
      .setCallbackFunction('authCallback')

      // Set the property store where authorized tokens should be persisted.
      .setPropertyStore(PropertiesService.getUserProperties())

      // Set the scopes to request (space-separated for Google services).
      .setScope('https://www.googleapis.com/auth/adwords')

      // Below are Google-specific OAuth2 parameters.

      // Sets the login hint, which will prevent the account chooser screen
      // from being shown to users logged in with multiple accounts.
      .setParam('login_hint', Session.getEffectiveUser().getEmail())

      // Requests offline access.
      .setParam('access_type', 'offline')

      // Consent prompt is required to ensure a refresh token is always
      // returned when requesting offline access.
      .setParam('prompt', 'consent');
}

There are also 2 other methods to redirect the user to authorize this application.

I believe the problem is the way I am structuring the request. I believe I need to supply more information to the API call in the makeRequest function. I have seen a 'payload' : JSON.stringify(request, null, 2) go in the headers section of the request function where request specifies a specific set of instructions to call from the API but I do not know how to structure that for this case. A solution would be super appreciated.