Error Importing 1 minute CSV data

Hi,

I am trying to write a program that takes in one-minute resolution historical data from a CSV file that is stored in DropBox. Here is a link to the DropBox file: I notice that every time I try to run the code, I don't get an error, but I get the message waiting for chart in the backtest screen. I tried waiting for over an hour and still notice that the message is the same. Could someone please help me understand what I am doing wrong in my code? 

Below is the code that I am running. 

# region imports
from AlgorithmImports import *
from datetime import datetime
from QuantConnect import *
from QuantConnect.Algorithm import *
from QuantConnect.Data import SubscriptionDataSource
from QuantConnect.Python import PythonData
import pandas as pd
# endregion

class PensiveMagentaAlligator(QCAlgorithm):
    def Initialize(self):
        self.SetStartDate(2023, 4, 1)
        self.SetEndDate(2023, 5, 3)
        self.SetCash(10000000)
        self.symbol = self.AddData(MyCustomDataType, "IBM", Resolution.Minute).Symbol


        self.SetWarmUp(300, Resolution.Minute)
    
    def OnData(self, data):
        if self.IsWarmingUp: return 
        hstv = self.History(self.symbol, 500, Resolution.Minute)
        histClose = pd.DataFrame(hstv)["close"]
        histHigh = pd.DataFrame(hstv)["high"]
        histLow = pd.DataFrame(hstv)["low"]

        self.Log(histClose[-1])



class MyCustomDataType(PythonData):
    def GetSource(self, config: SubscriptionDataConfig, date: datetime, isLive: bool) -> SubscriptionDataSource:
        return SubscriptionDataSource("https://www.dropbox.com/s/uiwrna3r9fqmxwa/IBM_Intraday.csv?dl=1", SubscriptionTransportMedium.RemoteFile)

    def Reader(self, config: SubscriptionDataConfig, line: str, date: datetime, isLive: bool) -> BaseData:
        if not (line.strip()):
            return None

        index = MyCustomDataType()
        index.Symbol = "IBM"

        try:
            data = line.split(',')


            index.Time = datetime.strptime(data[0], "%Y-%m-%d %H:%M:%S")
            index.Value = float(data[4])
            index["open"] = float(data[1])
            index["high"] = float(data[2])
            index["low"] = float(data[3])
            index["close"] = float(data[4])

        except ValueError:
            return None

        return index