@Ger-Buurman-0 OK. Probably you have some mobile device charger: Output:5.0V (= or DC) 0.5A (or 500mA) - more A (Amper) / mA (milliAmper) would be even better and it has micro USB plug. Plug it to the Micro USB Port of the Expansion Dock and switch on the Power Switch of the Dock.
After 2-3 minutes (the amber LED is not OFF / not dark - it is constantly ON / lit / illuminated) you should find a WiFi AP with SSID Omega-ABCD (ABCD is the last four characters on your Omega's sticker). Try to connect - password: 12345678
I have no Mac and I don't use / don't know Onion's web based stuff - I prefer the Command Line (CLI).
Try it Connecting to the Omega’s Command Line.