KeyError: 'OPTIONAL'

[DifCIO]

/opt/monitoring/zabbix-threat-control/prepare.py -uvtda
Traceback (most recent call last):
File "/opt/monitoring/zabbix-threat-control/prepare.py", line 25, in
from readconfig import *
File "/opt/monitoring/zabbix-threat-control/readconfig.py", line 18, in
zbx_verify_ssl = config['OPTIONAL'].getboolean('VerifySSL', True)
File "/usr/lib/python3.5/configparser.py", line 956, in getitem
raise KeyError(key)
KeyError: 'OPTIONAL'