There are different credentials to be used to connect to recovery SSID, depending on model and installed firmware. There was table published on support site showing versions and access data. Also it may be messed up when reset to factory was incomplete or unsuccessful. Usually it can be recovered, so.
I see that you use MacBook Pro, so you don't have Ethernet port. This is what I never liked about Apple laptops -- it is a nice peace of hardware, but it is not made for us, networking guys, as need to have an adapter to connect a wire is really a headache... Of case, they make them for management guys, who should never use Ethernet and even don't need to know what is it.
Problem is that nobody make really good laptops for our needs - I don't see any Wintel machine on market which is similar in build quality and price. You can get decent Wintel laptop, but it will be probably 2x more expensive than Apple nowadays, and still not that good.
So -- I would strongly recommend you to use the adapter or just get some PC with ethernet port to access APs by wire, you will save a lot of time, instead of troubleshooting recovery wireless connection and AP web management.
If something is wrong with web managemen, you'll need SSH access to AP anyway, either through direct wire connection or through some other working WiFi AP.
