Conference call and video (new to Asterisk administrator)

Dear Forum

I installed Magnus Billing onto a Linux Centos 7 (Jessie) minimal OS.
It was a straight installation where I ran the instruction provided by Magnus Billing.

I have the need to make Conferencall Call and Conference Video calls, but Magnus Billing reffered other users via forum to Asterisk as an option.
I have tried a couple of settings on the confbridge.conf file, which seemed easy since it is pre-populated, but it is not working.

Your kind support would be appreciated.
Please be gentle on a new administrator learning the ropes.

Without the configuration file and logs, no-one will be able to answer.