code: def list_forwarding_addresses(api_key, offset=None, coin_symbol='btc'):
      '''
      List the forwarding addresses for a certain api key
      (and on a specific blockchain)
      '''
  
      assert is_valid_coin_symbol(coin_symbol)
      assert api_key
  
      url = make_url(coin_symbol, 'payments')
  
      params = {'token': api_key}
  
      if offset:
          params['start'] = offset
  
      r = requests.get(url, params=params, verify=True, timeout=TIMEOUT_IN_SECONDS)
      return get_valid_json(rf list_forwarding_addresses(api_key, offset=None, coin_symbol='btc'):
      '''
      List the forwarding addresses for a certain api key
      (and on a specific blockchain)
      '''
  
      assert is_valid_coin_symbol(coin_symbol)
      assert api_key
  
      url = make_url(coin_symbol, 'payments')
  
      params = {'token': api_key}
  
      if offset:
          params['start'] = offset
  
      r = requests.get(url, params=params, verify=True, timeout=TIMEOUT_IN_SECONDS)
      return get_valid_json(r)
docs: List the forwarding addresses for a certain api key
      (and on a specific blockchain)