emberfire: emberfire install results in generate error message

Version info

DEBUG: Ember      : 3.10.1
DEBUG: Ember Data : 3.10.0
DEBUG: EmberFire  : 3.0.0-rc.3
DEBUG: jQuery     : 3.4.1
DEBUG: -------------------------------

Steps to reproduce

Run ember install emberfire@next, then ember serve. Attempt to save some data:

const newInvitation = this.store.createRecord('invitation', {email: email});
newInvitation.save()

Expected behavior

Emberfire should install and the data should send to the Firebase server and display on the server.

Actual behavior

Installing gives this:

$ ember install emberfire@next                                        
- Installing addon package                                            
- npm: Installing emberfire@next ...                                  
npm: Installed emberfire@next                                         
installing emberfire                                                  
The `ember generate ` command requires an entity name to  be specified. For more details, use `ember help`.
--

And attempting to save the data gives:

Failed to create an instance of 'adapter:application'. Most likely an improperly defined class or an invalid module export.