Transferring the file, prompting that the secret key file is too open, prints the following error.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions 0755 for ‘/data/user/lxb/.ssh/id_rsa’ are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
Load key “/data/user/lxb/.ssh/id_rsa”: bad permissions
[email protected]: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
rsync: connection unexpectedly closed (0 bytes received so far) [Receiver]
rsync error: unexplained error (code 255) at io.c(235) [Receiver=3.1.2]

The above printout is prompting you that the permissions granted to the private key file are too large.

Solution: $sudo chmod -R 700 /data/user/lxb/.ssh/
End.