Generate python UNIX timestamp

Question

I am working with the kraken and binance APIs. The binance API returns a time like this: 1612722603026 inside of the API response. The kraken API does not return a time for the API response so I am trying to generate a timestamp to match the one from binance in terms of format/units (UNIX). I tried using int(time.time()) but the result of this is: 1612722603 which when I convert to a date here gives me the date: 1970-01-19T15:58:42.602Z How can I generate a UNIX timestamp in python (one that matches the one from binance)? It seems to me that the one I am generating is 3 digits short