Android : Understanding app hashes on facebook app

When I try and click the button "Log in with Facebook", the loading animation appears and nothing happens. If I remove all hashes it opens the login screen but fails saying there are no hashes present. Am I supposed to be using developer or release hashes? What exactly am I missing here? I'm generating the hashes with this code:

try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    "PACKAGE",
                    PackageManager.GET_SIGNATURES);
            for (android.content.pm.Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                Log.wtf("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
        } catch (PackageManager.NameNotFoundException e) {

        } catch (NoSuchAlgorithmException e) {

        }