Hello.
After reading this whonix(.)org wiki Tor#Manual_Bridge_Configuration,
I’m trying to use obfs4 in whonix-cli gateway but getting the message you can read in the screenshot after checking it with sudo -u debian-tor tor --verify-config and also include the torrc.d/50_user.conf file
user@host:~$ sudo -u debian-tor tor --verify-config
Feb 01 16:03:45.248 [notice] Tor 0.4.6.8 running on Linux with Libevent 2.1.12-stable, OpenSSL 1.1.1k, Zlib 1.2.11, Liblzma 5.2.5, Libzstd 1.4.8 and Glibc 2.31 as libc.
Feb 01 16:03:45.249 [notice] Tor can't help you if you use it wrong! Learn how to be safe at https://www.torproject.org/download/download#warning
Feb 01 16:03:45.249 [notice] Read configuration file "/etc/tor/torrc".
Feb 01 16:03:45.253 [notice] Processing configuration path "/etc/torrc.d/" at recursion level 1.
Feb 01 16:03:45.254 [notice] Including configuration file "/etc/torrc.d//60_network.conf".
Feb 01 16:03:45.254 [notice] Including configuration file "/etc/torrc.d//65_gateway.conf".
Feb 01 16:03:45.255 [notice] Including configuration file "/etc/torrc.d//65_leak_tests.conf".
Feb 01 16:03:45.255 [notice] Including configuration file "/etc/torrc.d//70_workstation.conf".
Feb 01 16:03:45.256 [notice] Processing configuration path "/usr/share/tor/tor-service-defaults-torrc.anondist" at recursion level 2.
Feb 01 16:03:45.257 [notice] Including configuration file "/usr/share/tor/tor-service-defaults-torrc.anondist".
Feb 01 16:03:45.257 [notice] Including configuration file "/etc/torrc.d//95_whonix.conf".
Feb 01 16:03:45.258 [notice] Processing configuration path "/usr/local/etc/torrc.d/" at recursion level 2.
Feb 01 16:03:45.258 [notice] Including configuration file "/usr/local/etc/torrc.d//40_tor_control_panel.conf".
Feb 01 16:03:45.258 [notice] Including configuration file "/usr/local/etc/torrc.d//50_user.conf".
Feb 01 16:03:45.259 [warn] Option 'DisableNetwork' used more than once; all but the last value will be ignored.
Feb 01 16:03:45.260 [warn] Failed to parse/validate config: Unknown option 'obfs4'. Failing.
Feb 01 16:03:45.260 [err] Reading config failed--see warnings above.
user@host:~$ cat /usr/local/etc/torrc.d/50_user.conf
# Tor user specific configuration file
#
# Add user modifications below this line:
############################################
UseBridges 1
ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy
obfs4 212.227.73.134:10443 C37EEBDDC841549D348712E2A28EBDE8C6E8AD6C cert=ZVzHDRMDtno8qhi401uU86s8oyIbobl6Vw8Y66p6xJLMf1Czgdp2uZKwoWJmWVQn1l8aXw iat-mode=0
obfs4 109.238.14.174:587 AD9FCB8CF7DECAE1E885EEF1E4BC686CF75AC0A0 cert=fqLG7tU1fh1zIEVdkbc5qEcdZVo43oO3yVwa5FW0PsstyWEB+HhUpb9cIF7CZteJy26hNA iat-mode=0
obfs4 185.177.207.122:12346 A3339810B454962942B6B89A76F60EE1CFEF2611 cert=p9L6+25s8bnfkye1ZxFeAE4mAGY7DH4Gaj7dxngIIzP9BtqrHHwZXdjMK0RVIQ34C7aqZw iat-mode=2
obfs4 213.188.244.24:9003 B934C2D6AF3FF4CA3E83C2083B9CB0C526B059C8 cert=3oEFpT//HTYDhTi/VtFHNT6yHJjDPEACsa1wiJSOHiT5zekgrFW8SApInm1/4ApZ9qU7DQ iat-mode=0
obfs4 130.44.131.139:21550 A85BB204DBAB68B754FECEFF883B2F97A6FA71CD cert=tKWQMfH+fJSp5QobD1yQOm2BNZTZgmf3btXYsYQPXT5wd+I0rCvuz4jEbNuUhVnkC2hKcA iat-mode=0
obfs4 34.255.123.165:52176 EFF298A7FB2A1056189C5C12B46CD912AA77B16A cert=5CLOANyguG1hzulvbHZNlWy2BoMGk/VTAyfKvA7S0w0v/24XIYTz5tWlKWbyrZhxPEvWFA iat-mode=0