I’ll have a go, as you seem to be confusing what to put where etc…
1.connect laptop to Beryl (MT 1300) using wifi (eg. something like “MT1300-xxx” or “MT1300-5G-xxx”).
2. using browser go to 192.168.8.1 - on 1st boot you will be prompted to set language and change admin password (remember this!)
3. in the admin panel click on “wireless” and set-up your 2.4G and 5G wireless (you probably only need the 2.4G, so you can optionally turn off the 5G). Enter your preferred SSID (eg. corvette or corvette2 and corvette5 if you wish to setup both 2.4G and 5G), select WPA2-PSK (security), enter a new wifi key (eg. goodlife2), 802.11 b/g/n (mode), and leave everything else as is. Click “apply”.
4. Now your laptop will be disconnected from the Beryl and you have to reconnect to the new SSID you just entered (eg. corvette). WIndows will ask for the key you entered (goodlife2).
5. reconnect to the admin panel, 192.168.8.1, using the new admin password you set up in step2.
5. Now you are ready to connect to the internet (Captive Portal). Click internet then “scan” in the repeater box (this is clearly explained in the above video 3:50-4:25). When you test at home, the network you are looking for iis your Netgear Nighthawk.