Linkedin API request dateRange end today or now - linkedin-api

Question

I'm using Python 3 to request share statistics from Linkedin API for the last 14 months.
It works fine, when I hardcoded the epoch values in the request link:
https://api.linkedin.com/v2/organizationalEntityShareStatistics?q=organizationalEntity&organizationalEntity=urn%3Ali%3Aorganization%3AXXXXX&timeIntervals=(timeRange:(start:1596206929000,end:1632938933000),timeGranularityType:DAY)
Obviously I don't want to be changing the end values each time I make a request, so I thought I'd declare a variable:
from datetime import datetime
epochcdt = datetime.now().timestamp()
And then just use it in the link instead of the hardcoded value:
https://api.linkedin.com/v2/organizationalEntityShareStatistics?q=organizationalEntity&organizationalEntity=urn%3Ali%3Aorganization%3AXXXXX&timeIntervals=(timeRange:(start:1596206929000,end:epochcdt),timeGranularityType:DAY)
But, that doesn't work:
{'message': 'Internal Server Error', 'status': 500}
Can you please help me with this hopefully, easy to solve problem?
Whole code:
import requests
import json
from liapiauth import auth, headers
from datetime import datetime
epochcdt = (datetime.now().timestamp())*1000
def organization_info(headers):
response = requests.get('https://api.linkedin.com/v2/organizationalEntityShareStatistics?q=organizationalEntity&organizationalEntity=urn%3Ali%3Aorganization%3AXXXXX&timeIntervals=(timeRange:(start:1596206929000,end:{epochcdt}),timeGranularityType:DAY)', headers = headers)
organization_info = response.json()
return organization_info
if __name__ == '__main__':
credentials = 'credentials.json'
access_token = auth(credentials)
headers = headers(access_token)
organization_info = organization_info(headers)
with open('lishare14m.json', 'w') as outfile:
json.dump(organization_info, outfile)
print(organization_info)