code: async function setPreferredMcpSettings(accessToken, languageCode, languageTag, timezone) {
      let preferredLanguage = getValidLanguageOrThrow(languageCode);
      let preferredRegionalSettings = getValidLanguageTagOrThrow(languageTag);
      let preferredTimezone = getValidTimezoneOrThrow(timezone);
  
      const mcpSettings = await getMcpSettings(accessToken);
  
      return await mcpCustomizr.putSettings(accessToken, {
          language: updatePreferredLanguage(preferredLanguage, mcpSettings.language),
          regionalSettings: preferredRegionalSettings,
          timezone: preferredTimezone,
      });
  }
docs: Validate and update the preferred user settings at once
  @param {string} accessToken - Access token to use to call Customizr
  @param {string} languageCode - ISO-639 language code (eg. bul, en, eng, de)
  @param {string} languageTag - RFC 4656 compliant language code (eg. en, en-US)
  @param {string} timezone - IANA timezone (eg. Europe/Amsterdam)
  @return {Promise<void>}