Re-verified with documentation:

$ lxc launch ubuntu:focal test-rsync-receiver
$ lxc exec test-rsync-receiver bash
# apt update && apt dist-upgrade -y
# apt install openssh-server rsync -y

# passwd ubuntu
New password:
Retype new password:
passwd: password updated successfully

# sed -i 's/PasswordAuthentication no/PasswordAuthentication yes/' /etc/ssh/sshd_config
# systemctl restart sshd

# exit

- Check ip of receiver with lxc list
$ lxc list

+---------------------+---------+----------------------+-----------------------------------------------+-----------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+---------------------+---------+----------------------+-----------------------------------------------+-----------+-----------+
| test-rsync-receiver | RUNNING | 10.190.23.243 (eth0) | -------------------------------------- (eth0) | CONTAINER | 0 |
+---------------------+---------+----------------------+-----------------------------------------------+-----------+-----------+

$ lxc launch ubuntu:focal test-rsync-sender
$ lxc exec test-rsync-sender bash

# cat <<EOF >/etc/apt/sources.list.d/ubuntu-$(lsb_release -cs)-proposed.list
# Enable Ubuntu proposed archive
deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -cs)-proposed restricted main multiverse universe
EOF

# apt update && apt dist-upgrade -y

# apt install rsync -y

# rsync --help

...
 -s, --protect-args          no space-splitting; only wildcard special-chars
     --trust-sender          trust the remote sender's file list
     --address=ADDRESS       bind address for outgoing socket to daemon
...

# man rsync

...
       --trust-sender
              Disable the extra validation of the file list from a remote sender (this safety feature was added to address the performance downgrade after
              fixing CVE 2022-29154).  This should only be done if you trust the sender to not try to do something malicious, which should be the case  if
              they're running a stock rsync.

              Normally when pulling files from a remote rsync, the client runs 2 extra validation checks:

              o      Verify that additional arg items didn't get added at the top of the transfer.

              o      Verify that none of the items in the file list should have been excluded.

              Note that various options can turn off one or both of these checks if the option interferes with the validation.  For instance:

              o      Using a per-directory filter file reads filter rules that only the server knows about, so the filter checking is disabled.

              o      Using the --old-args option allows the sender to manipulate the requested args, so the arg checking is disabled.

              o      Reading the files-from list from the server side means that the client doesn't know the arg list, so the arg checking is disabled.

              o      Using --read-batch disables both checks since the batch file's contents will have been verified when it was created.

              This option may help an under-powered client server if the extra pattern matching is slowing things down on a huge transfer.  It can also be
              used to work around a bug in the verification logic, possibly after using the --list-only option combined with --trust-sender to  look  over
              the full file list.
...

# dd if=/dev/urandom of=randomfile.bin bs=1M count=1000

# rsync -av randomfile.bin ubuntu@10.190.23.243:~/file1.bin
ubuntu@10.190.23.243's password:
sending incremental file list
randomfile.bin

sent 1,048,832,093 bytes  received 35 bytes  99,888,774.10 bytes/sec
total size is 1,048,576,000  speedup is 1.00

# rsync -av --trust-sender randomfile.bin ubuntu@10.190.23.243:~/file2.bin
ubuntu@10.190.23.243's password:
sending incremental file list
randomfile.bin

sent 1,048,832,093 bytes  received 35 bytes  139,844,283.73 bytes/sec
total size is 1,048,576,000  speedup is 1.00