As per you comment, your application is in progress. So till the time (until you publish it) you can not mark your application live.
So Facebook gives a way to use facebook API including login before publishing app using test or dev users. You need to add set of user with defined role as test or dev. For those users you can use login api or other facebook api.
Read more at How to create Test Users for Apps
Or you can add some facebook users in role section available like below

Here you need to add id. For example if user's profile url is https://www.facebook.com/userAtFacebook
, id which you will add is userAtFacebook
. After adding that user userAtFacebook
will get notification to accept invite. That user needs to accept that. And that's it.