Need a replacement power supply - cannot get your support website to work

If you have not already done so unplug you power supply from the plug for 5 minutes to allow it to reset and when you power it back up try plugging it directly into a wall outlet to see what happens. When the power supply is unplugged also check to make
sure all connections and leads to and from the power supply are secure.

did you go to https://myservice.xbox.com ? it should let you "replace an accessory " ....

You will need to find the manufacturer's website (or seller's return policy) for more information about any possible warranty replacement, or just replace it with a Microsoft-branded power supply. This is, however, provided that this power supply hasn't
already caused damage to your console.

Since it's a third-party (non-Microsoft) power supply, the support forums cannot assist further with troubleshooting your device.

Unfortunately, it looks like the 'brick' needs to be replaced from the xbox support website.

Source https://beta.support.xbox.com/help/hardware-network/console/reset-power-supply-solution#if-the-led-is-off-or-blinking

If the LED is off or blinking

The power supply unit needs to be replaced. You need to replace the power supply unit if the light is still off or flashing orange. For in-warranty consoles, you can order a replacement Xbox One power supply unit
from
Device Support. You must register your product online to replace the unit under warranty. (The power supply warranty is the same as your console warranty.)

You can get a replacement power supply on the device support website.

Go to https://devicesupport.microsoft.com

There register the console with the faulty power supply, if not already done so.

Click on the console and select the issue you have with that console, and order a replacement power supply.