Using ctrader-fix to download historical data from cTrader - python-3.x

Question

I am using the python package ctrader-fix (https://pypi.org/project/ctrader-fix/) to download historical price data from ctrader's API (https://help.ctrader.com/fix/).
The code does not make clear to me at least where exactly I declare the symbol (e.g. 'NatGas') through its SymbolID code number (in the case of 'NatGas' the SymbolID code number is 10055) for which I request historical data but also it does not make clear where I specify the timeframe I am interested on (e.g. 'H' for hourly data) and the number of records I want to retrieve.
section of ctrader where the FIX SymbolID number of 'NatGas' is provided
The code that is provided is the following (I have filled the values except the username).
config = {
'Host': '',
'Port': 5201,
'SSL': False,
'Username': '****************',
'Password': '3672075',
'BeginString': 'FIX.4.4',
'SenderCompID': 'demo.pepperstoneuk.3672025',
'SenderSubID': 'QUOTE',
'TargetCompID': 'cServer',
'TargetSubID': 'QUOTE',
'HeartBeat': '30'
}
client = Client(config["Host"], config["Port"], ssl = config["SSL"])
def send(request):
diferred = client.send(request)
diferred.addCallback(lambda _: print("\nSent: ", request.getMessage(client.getMessageSequenceNumber()).replace("", "|")))
def onMessageReceived(client, responseMessage): # Callback for receiving all messages
print("\nReceived: ", responseMessage.getMessage().replace("", "|"))
# We get the message type field value
messageType = responseMessage.getFieldValue(35)
# we send a security list request after we received logon message response
if messageType == "A":
securityListRequest = SecurityListRequest(config)
securityListRequest.SecurityReqID = "A"
securityListRequest.SecurityListRequestType = 0
send(securityListRequest)
# After receiving the security list we send a market order request by using the security list first symbol
elif messageType == "y":
# We use getFieldValue to get all symbol IDs, it will return a list in this case
# because the symbol ID field is repetitive
symboldIds = responseMessage.getFieldValue(55)
if config["TargetSubID"] == "TRADE":
newOrderSingle = NewOrderSingle(config)
newOrderSingle.ClOrdID = "B"
newOrderSingle.Symbol = symboldIds[1]
newOrderSingle.Side = 1
newOrderSingle.OrderQty = 1000
newOrderSingle.OrdType = 1
newOrderSingle.Designation = "From Jupyter"
send(newOrderSingle)
else:
marketDataRequest = MarketDataRequest(config)
marketDataRequest.MDReqID = "a"
marketDataRequest.SubscriptionRequestType = 1
marketDataRequest.MarketDepth = 1
marketDataRequest.NoMDEntryTypes = 1
marketDataRequest.MDEntryType = 0
marketDataRequest.NoRelatedSym = 1
marketDataRequest.Symbol = symboldIds[1]
send(marketDataRequest)
# after receiving the new order request response we stop the reactor
# And we will be disconnected from API
elif messageType == "8" or messageType == "j":
print("We are done, stopping the reactor")
reactor.stop()
def disconnected(client, reason): # Callback for client disconnection
print("\nDisconnected, reason: ", reason)
def connected(client): # Callback for client connection
print("Connected")
logonRequest = LogonRequest(config)
send(logonRequest)
# Setting client callbacks
client.setConnectedCallback(connected)
client.setDisconnectedCallback(disconnected)
client.setMessageReceivedCallback(onMessageReceived)
# Starting the client service
client.startService()
# Run Twisted reactor, we imported it earlier
reactor.run()
Can you explain the code to me and provide instructions on how to get for example hourly data for NatGas (1,000 observations)?`