Show adb backup manual How do I show the help text/manual for adb backup?

When I run adb help I see


  ...
  backup/restore:
  &nbsp;&nbsp;&nbsp;&nbsp;to show usage run "adb shell bu help"
  ...


When I run adb shell bu help, nothing happens. What am I doing wrong?
That's because you need to connect a device to adb first. Check for connected devices, using adb devices.

Otherwise, it'll display an error:

C:\Users\User\AppData\Local\Android\Sdk\platform-tools&gt;adb shell bu help
error: no devices/emulators found


When you've connected device, run adb shell bu help - it will output something similar:

C:\Users\User\AppData\Local\Android\Sdk\platform-tools&gt;adb shell bu help
 backup [-f FILE] [-apk|-noapk] [-obb|-noobb] [-shared|-noshared] [-all]
        [-system|-nosystem] [-keyvalue|-nokeyvalue] [PACKAGE...]
     write an archive of the device's data to FILE [default=backup.adb]
     package list optional if -all/-shared are supplied
     -apk/-noapk: do/don't back up .apk files (default -noapk)
     -obb/-noobb: do/don't back up .obb files (default -noobb)
     -shared|-noshared: do/don't back up shared storage (default -noshared)
     -all: back up all installed applications
     -system|-nosystem: include system apps in -all (default -system)
     -keyvalue|-nokeyvalue: include apps that perform key/value backups.
         (default -nokeyvalue)
 restore FILE             restore device contents from FILE