I have just purchased the device. I updated it, enabled developer options and enabled OEM. I enter Fastboot mode to start the web installation and no browser or computer detects the device in the browser (although it makes the typical sound of when you connect a device to Windows). I do not know what can be due, I have already factory reset several times, I've tried with the USB cable that brings and my previous phone but no way. When I exit fastboot mode it detects everything normally (I have tried Brave and Edge).
Thanks you.

    There are multiple threads on these issues. Typically you either do not have the correct Google pixel drivers installed, or it could be the data cable that is faulty or only suitable for charging purposes without data transfer.
    It's a process of elimination. With the correct drivers, you should be able to test the link using commands such as adb devices, adb devices reboot bootloader. There is a fastboot one to, but don't recall just now what it is.

    I had this problem when I used the original cable with an usb-a adapter. Do you connect directly to USB c or do you use an adapter? If you use an adapter you should buy a cable a to c, that worked in my case.

    Stark Per the GrapheneOS web installation instructions here:

    https://grapheneos.org/install/web#connecting-phone

    You will need to either run Windows Update manually after connecting the phone while it is in its bootloader interface mode to get the correct driver installed, or install the necessary driver yourself by downloading it from Google and installing it manually:

    https://developer.android.com/studio/run/win-usb

    Cheers, and welcome to GrapheneOS!

      I did it but forgot to delete it, thanks. Indeed driver failure, thank you!