sudo apt install atftp

atftp [options] [host [port]]

-g, --get
    Non interactive invocation only. Instruct atftp to get file.
--mget
    Non interactive invocation only. Used to get file from a mtftp capable server.
-p, --put
    Non interactive invocation only. Instruct atftp to put file.
-l, --local-file
    Non interactive invocation only. The client side file name to read or write. Must be used in conjunction with --get or --put.
-r, --remote-file
    Non interactive invocation only. The server side file name to get or put. Must be used in conjunction with --get or --put.
--tftp-timeout <value>
    Number of seconds for timeout, client side. Default is 5 seconds.
--option <"name value">
    Set option "name" to "value". This command support exactly the same arguments as the interactive one. For example, use: --option "blksize 1428" to configure block size.
--mtftp <"name value">
    Set mtftp possible options. Accept the same options as the interactive mtftp command. For example, use: --mtftp "client-port 76" to configure client side port to use.
--no-source-port-checking
    See atftpd's man page.
--verbose
    Instruct atftp to be verbose. It will print more information about what's going on.
--trace
    This is useful for debugging purpose to display all packet going to and from the network.
-V, --version
    Print version.
-h, --help
    Print a summary of command line arguments.

sudo mkdir /tftp
sudo chown nobody: /tftp
sudo atftpd --daemon --port 69 /tftp

$ tftp -i 10.10.10.10 put secrets.txt
Transfer successful: 1337420 bytes in 69 second(s), 1337 bytes/s