Answer by Quandary for scp'ing using key file as a parameter, How can I do that if possible?

I usually use this:

scp -P <port_if_not_22> -i <path_to_keyfile> <source> <target>

example:

scp -P 666 -i "T:\.ssh\id_rsa" "D:\somePath\someFile.txt" root@78.24.82.66:/root/Downloads/someFile.txt