code: def _determine_checkout_url(self, platform, action):
          
          api_version = settings.API_CHECKOUT_VERSION
          if platform == "test":
              base_uri = settings.ENDPOINT_CHECKOUT_TEST
          elif self.live_endpoint_prefix is not None and platform == "live":
              base_uri = settings.ENDPOINT_CHECKOUT_LIVE_SUFFIX.format(
                  self.live_endpoint_prefix)
          elif self.live_endpoint_prefix is None and platform == "live":
              errorstring = """Please set your live suffix. You can set it
                     by running 'settings.
                     ENDPOINT_CHECKOUT_LIVE_SUFFIX = 'Your live suffix'"""
              raise AdyenEndpointInvalidFormat(errorstring)
          if action == "paymentsDetails":
              action = "payments/details"
          if action == "paymentsResult":
              action = "payments/result"
          if action == "originKeys":
              api_version = settings.API_CHECKOUT_UTILITY_VERSION
  
          return '/'.join([base_uri, api_version, action])
docs: This returns the Adyen API endpoint based on the provided platform,
          service and action.
  
          Args:
              platform (str): Adyen platform, ie 'live' or 'test'.
              action (str): the API action to perform.