I had been using BSNL Broadband with a Belkin N150 Wireless Modem + Router. But shifted to a Fiber To Home Service. It has a GPON ONT which provides a RJ45 output. I would like to know, if this can be used along with the Belkin Modem-Router with it functioning as a Router only. It doesn't have a Ethernet input port but 4 LAN output ports. I tried plugging it into one of the 4 output ports. The service connects, but it doesn't work for more than a single device at a time and the Router's setting page is unavailable as long as the Ethernet cable from the FTTH Modem is plugged into the LAN port.
Also, the FTTH service requires me to input the username and password as shown in the screenshot. Can I configure the router so as to avoid this while accessing Wi-Fi from phone.

Also, the FTTH service requires me to input the username and password as shown in the screenshot. Can I configure the router so as to avoid this while accessing Wi-Fi from phone.
