"debug1: No xauth program."

https://unix.stackexchange.com/questions/552601/no-xauth-program-cannot-forward-x11 I got the following error when tried the command.

$ ssh -v -X name@host
...
debug1: No xauth program.
Warning: No xauth data; using fake authentication data for X11 forwarding.
...

According to the above, I have the following line in /etc/ssh/sshd_config on the host already. Does anybody know how to fix this problem?

$ grep  XAuthLocation /etc/ssh/sshd_config
XAuthLocation /usr/bin/xauth
$ which xauth
/usr/bin/xauth
$ xauth version
1.1