I searched for a long time and try it by myself,all of not work I realized that the problem was not that simple. So I go to next way.
I found the Message give me
key_load_public: no such file or directory,this message cause me to focus on this direction .As you know it still don’t work well,when you check the connection with command
ssh -T email@example.com -vvv you can get the same message of the key_load even if you can connect properly.
I saw a message when I very upset,It is
Connecting to github.com port 21473,Holy S**t as you know the ssh default port is 22 ,I am stupid to use
21473 connect the github, I recall that I have changed the local ssh port. so I type
ssh -T -p 22 firstname.lastname@example.org it worked well.
There have to ways to solve this,the first way is change the ssh port to default value
22,the second way use Using SSH over the HTTPS port
Enjoy your coding time and focus on the error message.