I'm not sure that you can do this. As I understand it you can only associate a Badgr badge with the completion of a module. So you need to build the module and define the module completion requirements. If you've integrated Badgr into the course you should then be able to assign a pre-defined badge with the module. Users will earn this badge when they successfully complete the module.
Hope that helps ... I realise it's not the info you were actually looking for!