For Github connector, you needs to define at the application level on which projet the issue will be created using parameter organisation/repo
For example for repo https://github.com/cerberustesting/cerberus-sample-application organisation/repo should be :
cerberustesting/cerberus-sample-application
Optionaly you can define a label that will be added to issue created. ex : bug
In order to plug Cerberus to Github the parameter : cerberus_github_apitoken needs to be defined with a valid api token.
From your github account firt go to Developper settings menu

Then, select token

Then, Generate New Token

Then, Chosse a name, a duration and select the repo scopes

The generated token needs to be paste to cerberus_github_apitoken parameter.