nixpkgs/nixos/doc/manual/configuration/network-manager.xml

<section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-networkmanager">
 <title>NetworkManager</title>

 <para>
  To facilitate network configuration, some desktop environments use
  NetworkManager. You can enable NetworkManager by setting:
<programlisting>
<xref linkend="opt-networking.networkmanager.enable"/> = true;
</programlisting>
  some desktop managers (e.g., GNOME) enable NetworkManager automatically for
  you.
 </para>

 <para>
  All users that should have permission to change network settings must belong
  to the <code>networkmanager</code> group:
<programlisting>
<link linkend="opt-users.users._name_.extraGroups">users.users.alice.extraGroups</link> = [ "networkmanager" ];
</programlisting>
 </para>

 <para>
  NetworkManager is controlled using either <command>nmcli</command> or
  <command>nmtui</command> (curses-based terminal user interface). See their
  manual pages for details on their usage. Some desktop environments (GNOME,
  KDE) have their own configuration tools for NetworkManager. On XFCE, there is
  no configuration tool for NetworkManager by default: by enabling <xref linkend="opt-programs.nm-applet.enable"/>, the
  graphical applet will be installed and will launch automatically when the graphical session is started.
 </para>

 <note>
  <para>
   <code>networking.networkmanager</code> and <code>networking.wireless</code>
   (WPA Supplicant) can be used together if desired. To do this you need to instruct
   NetworkManager to ignore those interfaces like:
<programlisting>
<xref linkend="opt-networking.networkmanager.unmanaged"/> = [
   "*" "except:type:wwan" "except:type:gsm"
];
</programlisting>
   Refer to the option description for the exact syntax and references to external documentation.
  </para>
 </note>
</section>