How to install a script as a windows service?

Question

Python

Tell me pliz - there is a script that performs its usual pythonic affairs (according to the schedule it goes to FTP, parses something there, then saves it all to the database). I decided to install this script as a Windows service. I use NSSM for this . And it seems to be installed and launched, but nothing works. Installed by specifying the address of the python and the script as an argument. The second option - chose a batch file launching a script. What am I doing wrong???