David,
I have written a working and tested example using Win 10 Pro, and PHP
v7.4.14 with pecl-ssh2 v1.2.
https://gist.github.com/sikofitt/3c6818648874ce091006ff58f8f489c4
There are 2 examples of copying via ssh2.sftp:// stream and the
ssh2_scp_send function. Also a directory iterator example.
https://www.php.net/manual/en/wrappers.ssh2
https://www.php.net/manual/en/function.ssh2-scp-send
It sounds like you have found the private and public keys and had them
working using ssh from the command line. You can also pass the '-v'
switch to the ssh program and it will tell you exactly what it is doing
to connect.
Hope this helps!
Eric
