Hello @tom2!
I guess your check command contains something like this:
command = [ "C:\\Program Files\\ICINGA2/sbin/check_login.py" ]
Have you tried to adjust it as follows?
command = [ "C:\\Program Files\\PATH\\TO\\YOUR\\PYTHON\\INTERPRETER.EXE", "C:\\Program Files\\ICINGA2/sbin/check_login.py" ]
Best,
AK