Will reset button wipe all ISP/PPPoE settings on Zyxel EMG3525-T50B router?

I recently discovered my children accidentally removed remote management settings on a Zyxel EMG3525-T50B router. It is not the main router in our household, it is connected to another router - by ethernet cable - it was provided by the ISP. I read that it is a WAN connection or something like that. And, all devices are connected to this Zyxel router.

I'm currently unable to load the web interface to manage the router, but the router can still provide internet access. I tried to connect via the ethernet cable also, but it also didn't work.

So what I wanted to know, is if i use the reset button, will it destroy all the ISP stuff? Or, is just to reset the passwords and local settings of the router only? I want so save myself some time before having to call the ISP for setting all over again.