Run command:
echo $SSH_AUTH_SOCK
Output should be something like this:
/private/tmp/com.apple.launchd.QbuGHcegZA/Listeners
Now add this to your config:
"agent": "/private/tmp/com.apple.launchd.QbuGHcegZA/Listeners",
"privateKeyPath": "/Users/sebastian/.ssh/id_rsa",
"passphrase": null
Where ‘agent’ should be the output of the command above and the ‘privateKeyPath’ should be the path to your id_rsa.pub.
‘passphrase’ is null or ‘your_password’.