Why can't Xshell connect to ssh by key?

Question

SSH

There is an Xshell program for working with ssh.
I am generating keys to connect to a server remotely. The server is deployed on a VirtualBox virtual machine (OS - CentOS 7)
A git user has been created on the VM to work with its own git repo.
In /home/git/.ssh, as expected, I put the pub key.
Doesn't want to join any. And I generated the key through the utility itself and through the git-bash console, and copied it over everything (both as a line and as a file). When I try to connect, it says

Answer 1

Hi,
Git user is not equal to git user. CentOS is case sensitive.