SAFARI CAN NOT OPEN THE PAGE BECAUSE THE SERVER CAN NOT BE FOUND. I need to unplud the router to fix

Some things just don't work in Safari is Netgear's manuals are to be believed. That includes the RBR20. For example, it says that it does not support the reset process. Have you tried a different browser?

You have posted your message in the section of this community given over to Nighthawk WiFi Routers. (This is easily done, given Netgear's complicated community structure.)

Many questions apply to different types of device, so there may be useful responses here, But Orbi systems use different technology from Nighthawk routers so you might get more help, and find earlier questions and answers specific to your device, in the appropriate section for your hardware. That's probably here:

Orbi - NETGEAR Communities

I will ask the Netgear moderator to move your message.

In the meantime you could visit the support pages:

Support | NETGEAR

Feed in your model number and check the documentation for your hardware.

You may have done this already. I can't tell from your message.

I mention it because Netgear stopped supplying printed manuals and CD versions some years ago and people sometimes miss the downloads.