Need help with Level Service time

Hello every one, i have the following situation:
I need to change the value “Service Level” to 20 sec.
the options in the web interface dont show this value, only intervals of 15 sec.
Many thanks

The user interface for Asterisk is a text file that allows values with a resolution of one second.

If you are using some other interface, please contact the people who wrote that interface.

For FreePBX, the community support is provided at

Asterisk GUI is no longer supported, except by vendors, so if this is part of an appliance you bought, please contact the vendor.