Credits: https://interworks.com/blog/2021/09/15/setting-up-ssh-agent-in-windows-for-passwordless-git-authentication/ and https://snowdrift.tech/cli/ssh/git/tutorials/2019/01/31/using-ssh-agent-git-windows.html
Use an elavated PowerShell windows and run the following commands.
To start the ssh-agent automatically
Get-Service ssh-agent | Set-Service -StartupType Automatic -PassThru | Start-Service
Set GIT_SSH environment variable
[Environment]::SetEnvironmentVariable("GIT_SSH", "$((Get-Command ssh).Source)", [System.EnvironmentVariableTarget]::User)
Add ssh keys to agent
ssh-add <path>