CLIENT ID : R946011

I am using the correct api_key and login credentials but getting following error:
Response: {'success': False, 'message': 'Invalid Token', 'errorCode': 'AG8001', 'data': ''}

When I run the following code:
obj = SmartConnect(api_key= api_key)
data = smartApi.generateSession(username, pwd, totp)
refreshToken = data['data']['refreshToken']
res = obj.getProfile(refreshToken)
params = {
"exchange": "NSE",
"symboltoken": "99926000",
"interval": "ONE_HOUR",
"fromdate": "2023-09-06 11:15",
"todate": "2023-09-06 12:00"
}

hist_data = obj.getCandleData(params);

Client Id : R946011
Getting the following error on connection :
Response: {'success': False, 'message': 'Invalid Token', 'errorCode': 'AG8001', 'data': ''}

I am running the below code:
params = {
"exchange": "NSE",
"symboltoken": "99926000",
"interval": "ONE_HOUR",
"fromdate": "2023-09-06 11:15",
"todate": "2023-09-06 12:00"
}

hist_data = obj.getCandleData(params);