I can't connect to Omega2 Access Point

I managed to set up my Omega2 using the GUI by connecting to the Access Point and setting up the wifi. However, when I go to cloud.onion.io and then Device Manager it says that my Omega2 is offline. So I wanted to connect to the Access Point again and make sure it was set up properly, but now I cannot connect; When trying to connect to "Omega-ABCD" it asks me to "Enter the network security key". The first time I did this I had to enter "12345678". But now it doesn't work anymore. It just says that the key is incorrect.

Thanks in advance.