FPT G-93RG1 in modem only mode?

Hi guys,

Sorry I am a French guy and I don't speak vietnamese. Hope you will still be able to help me.

I'm having a contract with FPT with Fiber and I am running on a G-93RG1 router.
The issue is, I have already a great router (ASUS) and I wish to configure the G-93RG1 as modem only (or bridge mode). Can I change this?

In fact I have a server running at home, but if I try to access to my website, I am only redirected to the G-93RG1 interface...(Even after forwarding the port 80 to the IP of my ASUS router)

Thanks for your help!